Fluvial sedimentary styles and associated depositional environments in the buntsandstein west of river rhine in saar area and pfalz (F.R. Germany) and vosges (France)

Science.gov (United States)

Dachroth, Wolfgang

The Buntsandstein west of river Rhine in Saar area, Pfalz and Vosges consists of three fluvial magnacycles which are characterized by different associated non-alluvial environments. The stratigraphic sequence is divided by several unconformities reflecting tectonic movements which were connected with periods of extension of the depositional area. Two major phases and two minor events are recognized by the evaluation of the Pfalz unconformity and the Lothringen unconformity, and the Leuter unconformity and the Saar unconformity, respectively. The Lower Buntsandstein (including Zechstein) compries the first magnacycle and is built up of alluvial-fan deposits, fluvial braidplain sediments and marine to lagoonal deposits. Some aeolian sands as well as several palaeosols are also present. The palaeolandscape consists of alluvial fans seaming the margin of the basin and fluvial braidplains reaching from the toes of the fan belt to the centre of the depositional area which is occupied by a lagoonal sea that partially evolves into a playa-lake with progressive refreshment. The Middle Buntsandstein comprises the second magnacycle and is composed of an alternation of aeolian Dünnschichten and fluvial Felsbänke. The third facies are alluvial-fan deposits of palaeogeographically restricted distribution along the margins of the basin. The aeolian Dünnschichten originate in the marginal parts of chott-type depressions (in comparison with the recent Chott Djerid in Tunesia) where rising ground water moistens the dry sediments that are laid down on the playa floor and thus allows their enhanced preservation. In dry periods, wind-blown sand is spread out as plane sheets or as migrating wind ripple trains, or accumulates to barchanoid-type dunes that advance across the flat. Depending on supply of sand, all stages of transition between dune fields with only narrow interdune corridors between the ridges and interdune playas with isolated widely-spaced dunes are developed. The

Axial Fan Blade Vibration Assessment under Inlet Cross-Flow Conditions Using Laser Scanning Vibrometry

Directory of Open Access Journals (Sweden)

Till Heinemann

2017-08-01

Full Text Available In thermal power plants equipped with air-cooled condensers (ACCs, axial cooling fans operate under the influence of ambient flow fields. Under inlet cross-flow conditions, the resultant asymmetric flow field is known to introduce additional harmonic forces to the fan blades. This effect has previously only been studied numerically or by using blade-mounted strain gauges. For this study, laser scanning vibrometry (LSV was used to assess fan blade vibration under inlet cross-flow conditions in an adapted fan test rig inside a wind tunnel test section. Two co-rotating laser beams scanned a low-pressure axial fan, resulting in spectral, phase-resolved surface vibration patterns of the fan blades. Two distinct operating points with flow coefficients of 0.17 and 0.28 were examined, with and without inlet cross-flow influence. While almost identical fan vibration patterns were found for both reference operating points, the overall blade vibration increased by 100% at the low fan flow rate as a result of cross-flow, and by 20% at the high fan flow rate. While numerically predicted natural frequency modes could be confirmed from experimental data as minor peaks in the vibration amplitude spectrum, they were not excited significantly by cross-flow. Instead, primarily higher rotation-rate harmonics were amplified; that is, a synchronous blade-tip flapping was strongly excited at the blade-pass frequency.

Synchronous and Cogged Fan Belt Performance Assessment

Energy Technology Data Exchange (ETDEWEB)

Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Acosta, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-02-01

The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

"The Waters of Meridiani" - Further Support for a Fluvial Interpretation of the Ridged, Layered Units

Science.gov (United States)

Wilkinson, Justin; Kreslavsky, Misha

2009-01-01

A relatively unknown terrestrial fluvial environment, the mesoscale megafan, provides analogs for various Martian landscapes, including the etched unit (etched unit, Unite E of Arvidson et al., 2003; ridge-forming unit R of Edgett, 2005) of the Sinus Meridiani region on Mars. A global survey of Earth shows that megafans are very large partial cones of dominantly fluvial sediment with radii on the order of hundreds of km, and very low slopes. Responsible fluvial processes are sufficiently different from those of classical arid alluvial fans and deltas that it is useful to class megafans as separate features. The megafan model calls into question two commonly held ideas. 1. Earth examples prove that topographic basins per se are unnecessary for the accumulation of large sedimentary bodies. 2. River channels are by no means restricted to valleys (Meridiani sediments are termed a "valley-ed volume" of Edgett). These perspectives reveal unexpected parallels with features at Meridiani-several channel-like features that are widespread, mostly as ridges inverted by eolian erosion; channel networks covering thousands of sq km, especially on intercrater plains; and regional relationships of sediment bodies situated immediately downstream of highland masses. These all suggest that fluvial explanations are at least part of the Meridiani story.

Protracted fluvial recovery from medieval earthquakes, Pokhara, Nepal

Science.gov (United States)

Stolle, Amelie; Bernhardt, Anne; Schwanghart, Wolfgang; Andermann, Christoff; Schönfeldt, Elisabeth; Seidemann, Jan; Adhikari, Basanta R.; Merchel, Silke; Rugel, Georg; Fort, Monique; Korup, Oliver

2016-04-01

River response to strong earthquake shaking in mountainous terrain often entails the flushing of sediments delivered by widespread co-seismic landsliding. Detailed mass-balance studies following major earthquakes in China, Taiwan, and New Zealand suggest fluvial recovery times ranging from several years to decades. We report a detailed chronology of earthquake-induced valley fills in the Pokhara region of western-central Nepal, and demonstrate that rivers continue to adjust to several large medieval earthquakes to the present day, thus challenging the notion of transient fluvial response to seismic disturbance. The Pokhara valley features one of the largest and most extensively dated sedimentary records of earthquake-triggered sedimentation in the Himalayas, and independently augments paleo-seismological archives obtained mainly from fault trenches and historic documents. New radiocarbon dates from the catastrophically deposited Pokhara Formation document multiple phases of extremely high geomorphic activity between ˜700 and ˜1700 AD, preserved in thick sequences of alternating fluvial conglomerates, massive mud and silt beds, and cohesive debris-flow deposits. These dated fan-marginal slackwater sediments indicate pronounced sediment pulses in the wake of at least three large medieval earthquakes in ˜1100, 1255, and 1344 AD. We combine these dates with digital elevation models, geological maps, differential GPS data, and sediment logs to estimate the extent of these three pulses that are characterized by sedimentation rates of ˜200 mm yr-1 and peak rates as high as 1,000 mm yr-1. Some 5.5 to 9 km3 of material infilled the pre-existing topography, and is now prone to ongoing fluvial dissection along major canyons. Contemporary river incision into the Pokhara Formation is rapid (120-170 mm yr-1), triggering widespread bank erosion, channel changes, and very high sediment yields of the order of 103 to 105 t km-2 yr-1, that by far outweigh bedrock denudation rates

Climate evolution during the Pleniglacial and Late Glacial as recorded in quartz grain morphoscopy of fluvial to aeolian successions of the European Sand Belt

Directory of Open Access Journals (Sweden)

Woronko Barbara

2015-06-01

Full Text Available We present results of research into fluvial to aeolian successions at four sites in the foreland of the Last Glacial Maximum, i.e., the central part of the “European Sand Belt”. These sites include dune fields on higher-lying river terraces and alluvial fans. Sediments were subjected to detailed lithofacies analyses and sampling for morphoscopic assessment of quartz grains. Based on these results, three units were identified in the sedimentary succession: fluvial, fluvio-aeolian and aeolian. Material with traces of aeolian origin predominate in these sediments and this enabled conclusions on the activity of aeolian processes during the Pleniglacial and Late Glacial, and the source of sediment supply to be drawn. Aeolian processes played a major role in the deposition of the lower portions of the fluvial and fluvio-aeolian units. Aeolian material in the fluvial unit stems from aeolian accumulation of fluvial sediments within the valley as well as particles transported by wind from beyond the valley. The fluvio-aeolian unit is composed mainly of fluvial sediments that were subject to multiple redeposition, and long-term, intensive processing in an aeolian environment. In spite of the asynchronous onset of deposition of the fluvio-aeolian unit, it is characterised by the greatest homogeneity of structural and textural characteristics. Although the aeolian unit was laid down simultaneously, it is typified by the widest range of variation in quartz morphoscopic traits. It reflects local factors, mainly the origin of the source material, rather than climate. The duration of dune-formation processes was too short to be reflected in the morphoscopy of quartz grains.

Fluvial geomorphology and river engineering: future roles utilizing a fluvial hydrosystems framework

Science.gov (United States)

Gilvear, David J.

1999-12-01

River engineering is coming under increasing public scrutiny given failures to prevent flood hazards and economic and environmental concerns. This paper reviews the contribution that fluvial geomorphology can make in the future to river engineering. In particular, it highlights the need for fluvial geomorphology to be an integral part in engineering projects, that is, to be integral to the planning, implementation, and post-project appraisal stages of engineering projects. It should be proactive rather than reactive. Areas in which geomorphologists will increasingly be able to complement engineers in river management include risk and environmental impact assessment, floodplain planning, river audits, determination of instream flow needs, river restoration, and design of ecologically acceptable channels and structures. There are four key contributions that fluvial geomorphology can make to the engineering profession with regard to river and floodplain management: to promote recognition of lateral, vertical, and downstream connectivity in the fluvial system and the inter-relationships between river planform, profile, and cross-section; to stress the importance of understanding fluvial history and chronology over a range of time scales, and recognizing the significance of both palaeo and active landforms and deposits as indicators of levels of landscape stability; to highlight the sensitivity of geomorphic systems to environmental disturbances and change, especially when close to geomorphic thresholds, and the dynamics of the natural systems; and to demonstrate the importance of landforms and processes in controlling and defining fluvial biotopes and to thus promote ecologically acceptable engineering. Challenges facing fluvial geomorphology include: gaining full acceptance by the engineering profession; widespread utilization of new technologies including GPS, GIS, image analysis of satellite and airborne remote sensing data, computer-based hydraulic modeling and

Late Pleistocene dune-sourced alluvial fans in coastal settings: Sedimentary facies and related processes (Mallorca, Western Mediterranean)

Science.gov (United States)

Pomar, F.; del Valle, L.; Fornós, J. J.; Gómez-Pujol, L.

2018-05-01

Aeolian-alluvial sedimentary interaction results in the formation of deposits characterized by typical alluvial sedimentary structures, but is composed of conspicuous amounts of aeolian sediments. The literature on this topic is limited and most works relate more with continental aeolian dunes or fluvial dune interference with fan bodies. Furthermore, there is a lack of examples of aeolian-alluvial sedimentary interference in coastal settings. In the western Mediterranean, there are many Pleistocene alluvial fan deposits built up partly by sediment originating from coastal dunes dismantled by alluvial streams. Very often, these deposits show a continuous sedimentary sequence through which we can derive the contribution and predominance of coastal, alluvial-colluvial and aeolian processes and their controls on landscape formation. This is an outstanding feature within coastal systems since it shows marine sediments reworked and integrated within coastal dune fields by aeolian transport, and the latter built up into alluvial fan bodies. In this sense, aeolian-alluvial interaction is the geomorphic-sedimentary expression of the coexistence and overlapping of alluvial and aeolian environments resulting in deposits sharing sedimentary features from both environments. The aim of this paper is to unravel the contribution of coastal dunes in the construction of alluvial fans bodies and identify the main sedimentary facies that constitute these deposits, as well as their climatic controls. For this reason, Es Caló fan (northern Mallorca) has been selected due to its well-exposed deposits exhibiting the alternation of aeolian, alluvial and colluvial deposits. Sedimentological and stratigraphic analyses based on 33 logs and complementary analyses demonstrate that most of the facies constituting the fan body are made up completely of marine bioclastic sands. These deposits record an alluvial fan sedimentary environment characterized by sediments inputs that do not proceed

High- and low-latitude forcing of the Nile River regime during the Holocene inferred from laminated sediments of the Nile deep-sea fan

NARCIS (Netherlands)

Blanchet, C.; Tjallingii, R.; Frank, M.; Lorenzen, J.; Reitz, A.; Brown, K.; Feseker, T.; Brückmann, W.

2013-01-01

Sediments deposited on deep-sea fans are an excellent geological archive to reconstruct past changes in fluvial discharge. Here we present a reconstruction of changes in the regime of the Nile River during the Holocene obtained using bulk elemental composition, grain-size analyses and radiogenic

Centrifugal fans: Similarity, scaling laws, and fan performance

Science.gov (United States)

Sardar, Asad Mohammad

Centrifugal fans are rotodynamic machines used for moving air continuously against moderate pressures through ventilation and air conditioning systems. There are five major topics presented in this thesis: (1) analysis of the fan scaling laws and consequences of dynamic similarity on modelling; (2) detailed flow visualization studies (in water) covering the flow path starting at the fan blade exit to the evaporator core of an actual HVAC fan scroll-diffuser module; (3) mean velocity and turbulence intensity measurements (flow field studies) at the inlet and outlet of large scale blower; (4) fan installation effects on overall fan performance and evaluation of fan testing methods; (5) two point coherence and spectral measurements conducted on an actual HVAC fan module for flow structure identification of possible aeroacoustic noise sources. A major objective of the study was to identity flow structures within the HVAC module that are responsible for noise and in particular "rumble noise" generation. Possible mechanisms for the generation of flow induced noise in the automotive HVAC fan module are also investigated. It is demonstrated that different modes of HVAC operation represent very different internal flow characteristics. This has implications on both fan HVAC airflow performance and noise characteristics. It is demonstrated from principles of complete dynamic similarity that fan scaling laws require that Reynolds, number matching is a necessary condition for developing scale model fans or fan test facilities. The physical basis for the fan scaling laws derived was established from both pure dimensional analysis and also from the fundamental equations of fluid motion. Fan performance was measured in a three times scale model (large scale blower) in air of an actual forward curved automotive HVAC blower. Different fan testing methods (based on AMCA fan test codes) were compared on the basis of static pressure measurements. Also, the flow through an actual HVAC

Computer fan performance enhancement via acoustic perturbations

Energy Technology Data Exchange (ETDEWEB)

Greenblatt, David, E-mail: davidg@technion.ac.il [Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa (Israel); Avraham, Tzahi; Golan, Maayan [Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa (Israel)

2012-04-15

Highlights: Black-Right-Pointing-Pointer Computer fan effectiveness was increased by introducing acoustic perturbations. Black-Right-Pointing-Pointer Acoustic perturbations controlled blade boundary layer separation. Black-Right-Pointing-Pointer Optimum frequencies corresponded with airfoils studies. Black-Right-Pointing-Pointer Exploitation of flow instabilities was responsible for performance improvements. Black-Right-Pointing-Pointer Peak pressure and peak flowrate were increased by 40% and 15% respectively. - Abstract: A novel technique for increasing computer fan effectiveness, based on introducing acoustic perturbations onto the fan blades to control boundary layer separation, was assessed. Experiments were conducted in a specially designed facility that simultaneously allowed characterization of fan performance and introduction of the perturbations. A parametric study was conducted to determine the optimum control parameters, namely those that deliver the largest increase in fan pressure for a given flowrate. The optimum reduced frequencies corresponded with those identified on stationary airfoils and it was thus concluded that the exploitation of Kelvin-Helmholtz instabilities, commonly observed on airfoils, was responsible for the fan blade performance improvements. The optimum control inputs, such as acoustic frequency and sound pressure level, showed some variation with different fan flowrates. With the near-optimum control conditions identified, the full operational envelope of the fan, when subjected to acoustic perturbations, was assessed. The peak pressure and peak flowrate were increased by up to 40% and 15% respectively. The peak fan efficiency increased with acoustic perturbations but the overall system efficiency was reduced when the speaker input power was accounted for.

Computer fan performance enhancement via acoustic perturbations

International Nuclear Information System (INIS)

Greenblatt, David; Avraham, Tzahi; Golan, Maayan

2012-01-01

Highlights: ► Computer fan effectiveness was increased by introducing acoustic perturbations. ► Acoustic perturbations controlled blade boundary layer separation. ► Optimum frequencies corresponded with airfoils studies. ► Exploitation of flow instabilities was responsible for performance improvements. ► Peak pressure and peak flowrate were increased by 40% and 15% respectively. - Abstract: A novel technique for increasing computer fan effectiveness, based on introducing acoustic perturbations onto the fan blades to control boundary layer separation, was assessed. Experiments were conducted in a specially designed facility that simultaneously allowed characterization of fan performance and introduction of the perturbations. A parametric study was conducted to determine the optimum control parameters, namely those that deliver the largest increase in fan pressure for a given flowrate. The optimum reduced frequencies corresponded with those identified on stationary airfoils and it was thus concluded that the exploitation of Kelvin–Helmholtz instabilities, commonly observed on airfoils, was responsible for the fan blade performance improvements. The optimum control inputs, such as acoustic frequency and sound pressure level, showed some variation with different fan flowrates. With the near-optimum control conditions identified, the full operational envelope of the fan, when subjected to acoustic perturbations, was assessed. The peak pressure and peak flowrate were increased by up to 40% and 15% respectively. The peak fan efficiency increased with acoustic perturbations but the overall system efficiency was reduced when the speaker input power was accounted for.

Being of service: "X-Files" fans and social engagement

Directory of Open Access Journals (Sweden)

Bethan Jones

2012-06-01

Full Text Available I explore the ways in which celebrity charity and fan activism can lead to civic engagement and social change. Fan studies has moved away from the traditional view of fans as psychologically deficient and has begun to examine resistance within the cultural productions of fandom—fan fiction, for example, addressing gender imbalances in popular TV shows. However, scholarship on celebrity-focused fans still retains much of the stigmatizing language that mars early writing about fans. I examine the relationship between celebrity and fan; examine the role celebrity plays in framing fan charity; assess how fan investment affects celebrity charity work; and argue that fans are active participants in encouraging social awareness and charitable giving.

Chronology of fluvial terrace sequences for large Atlantic rivers in the Iberian Peninsula (Upper Tagus and Duero drainage basins, Central Spain)

Science.gov (United States)

Silva, Pablo G.; Roquero, Elvira; López-Recio, Mario; Huerta, Pedro; Martínez-Graña, Antonio M.

2017-06-01

This work analyses the chronology of fluvial terrace sequences of the two most important fluvial basins from central Spain draining to the Atlantic Ocean (Upper Tagus and Duero drainage basins). Both basins evolved under similar Mediterranean climatic conditions throughout the Pleistocene and present comparable number of fluvial terraces (16-17) after excluding the higher terrace levels of the Tagus (T1-T5) entrenched in the Raña surface. These higher ;rañizo terraces; was formed in response to fan-head trenching in this high alluvial piedmont (+220 m) and therefore not properly controlled by Quaternary fluvial downcutting. The study accomplishes the implementation of multiple regression analyses for terrace height-age relationships. To transform relative terrace heights above the present river thalwegs (i.e. +100 m) in numerical ages a ;height-age transference function; has been developed on the basis of preliminary statistical geochronological approaches proposed for Central Spain. The resultant height-age transference function gather 73 published geochronological data for terrace sequences, featuring a 3rd Order Polynomial Function (R2 0.90). This function describes the overall trend of valley downcutting for the last c. 2.3 Ma in Central Spain and is used to assign numerical ages to terrace levels at different relative elevation.

Potential Global Benefits of Improved Ceiling Fan Energy Efficiency

Energy Technology Data Exchange (ETDEWEB)

Sathaye, Nakul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-10-31

Ceiling fans contribute significantly to residential electricity consumption, both in an absolute sense and as a proportion of household consumption in many locations, especially in developing countries in warm climates. However, there has been little detailed assessment of the costs and benefits of efficiency improvement options for ceiling fans and the potential resulting electricity consumption and greenhouse gas (GHG) emissions reductions. We analyze the costs and benefits of several options to improve the efficiency of ceiling fans and assess the global potential for electricity savings and GHG emission reductions with more detailed assessments for India, China, and the U.S. We find that ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terrawatt hours per year (TWh/year) could be saved and 25 million metric tons of carbon dioxide (CO2) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize this savings potential.

Mapping Variability in the Medusae Fossae Formation: Yardang Morphologies, Fluvial Reworking, and Crater Depth to Diameter Ratios

Science.gov (United States)

Khuller, A. R.; Kerber, L.

2017-12-01

The Medusae Fossae Formation (MFF) is a voluminous, fine-grained deposit thought to be of pyroclastic origin. While it contains widespread, well-preserved inverted fluvial features, its pervasive cover of dust means that little is known about its composition, and indirect means must be used to characterize its material properties. This project aims to correlate fluvial features in the Western MFF with other indicators of material strength: yardang morphology and crater depth-to-diameter ratios. For this work, Context Camera (CTX) images were used to map features of fluvial origin (inverted channels, sinuous ridges, alluvial fans). The presence of rounded, meso-yardangs in close proximity to fluvial features was also mapped. Crater depth-diameter (d/D) ratios (for craters 1-512km) were analyzed using a global Mars crater database (Robbins and Hynek, 2012) as a proxy for material strength. Approximately 1400 fluvial segments were mapped, with the most populous cluster located in Aeolis and Zephyria Plana. Rounded meso-yardangs were found to be common in areas that also have fluvial features. In agreement with previous work (Barlow, 1993), MFF craters were found to have a greater d/D ratio (0.0523) than the global mean (0.0511). Ratios between MFF lobes differ significantly, providing insight into the heterogeneity of induration within the formation. The deepest craters are found in Eumenides Dorsum and the shallowest in Aeolis Planum, consistent with a greater degree of induration and reworking in the western part of the formation where the fluvial features and "salt-playa" meso-yardangs are found. It also suggests that Eumenides, which is the tallest MFF outcrop, could also be the least compacted. The presence of long, complex, and sometimes overlapping branching networks imply multiple relative episodes of channel formation. Rounded meso-yardangs, which are associated with salt playa surfaces on Earth, provide additional evidence for the presence of liquid water

Evolution of tertiary intermontane fluvial system of Powder River Basin, Wyoming and Montana

International Nuclear Information System (INIS)

Flores, R.M.; Ethridge, F.G.

1985-01-01

Exploration and development of economic coal and uranium deposits of the Tertiary Fort Union and Wasatch Formations provided data related to the evolution of depositional systems in the Powder River Basin. In ascending order, the Paleocene Fort Union Formation consists of the Tullock, Lebo, and Tongue River Members. The overlying Eocene Wasatch Formation consists of the conglomeratic Kingsbury and Moncrief Members and laterally equivalent finer grained deposits. Evolution of fluvial deposition in the basin was determined from sandstone percent maps. A high proportion of sandstones in the Tullock Member and combined Tongue River Member and Wasatch Formation formed in interconnected east-west and north-south belts. The east-west belts represent alluvial fans, as well as braided and meandering tributary streams. The north-south belts reflect meandering and anastomosing trunk streams fed by basin margin tributaries. The sandstones of the Lebo Shale show east-west trends and represent deposits of fluvio-deltaic systems that filled a western, closed-lacustrine basin. The lake in this basin may have formed during localized subsidence along the Buffalo deep fault. These contrasting styles of fluvial deposition were largely controlled by extrabasinal and intrabasinal tectonics associated with Laramide orogeny

Computational Aerodynamic Simulations of a 1215 ft/sec Tip Speed Transonic Fan System Model for Acoustic Methods Assessment and Development

Science.gov (United States)

Tweedt, Daniel L.

2014-01-01

Computational Aerodynamic simulations of a 1215 ft/sec tip speed transonic fan system were performed at five different operating points on the fan operating line, in order to provide detailed internal flow field information for use with fan acoustic prediction methods presently being developed, assessed and validated. The fan system is a sub-scale, low-noise research fan/nacelle model that has undergone extensive experimental testing in the 9- by 15-foot Low Speed Wind Tunnel at the NASA Glenn Research Center. Details of the fan geometry, the computational fluid dynamics methods, the computational grids, and various computational parameters relevant to the numerical simulations are discussed. Flow field results for three of the five operating points simulated are presented in order to provide a representative look at the computed solutions. Each of the five fan aerodynamic simulations involved the entire fan system, which for this model did not include a split flow path with core and bypass ducts. As a result, it was only necessary to adjust fan rotational speed in order to set the fan operating point, leading to operating points that lie on a fan operating line and making mass flow rate a fully dependent parameter. The resulting mass flow rates are in good agreement with measurement values. Computed blade row flow fields at all fan operating points are, in general, aerodynamically healthy. Rotor blade and fan exit guide vane flow characteristics are good, including incidence and deviation angles, chordwise static pressure distributions, blade surface boundary layers, secondary flow structures, and blade wakes. Examination of the flow fields at all operating conditions reveals no excessive boundary layer separations or related secondary-flow problems.

Implications of sedimentological studies for environmental pollution assessment and management: Examples from fluvial systems in North Queensland and Western Australia

Science.gov (United States)

Eyre, Bradley; McConchie, David

1993-05-01

Sedimentology is of increasing importance in environmental research, particularly environmental pollution studies, where past trends in environmental processes need to be combined with data on present conditions to predict likely future changes—the past and present as a key to the future. Two examples are used to illustrate the role of sedimentology in assessing the influence of major processes on the transport, accumulation, deposition and modification of contaminants in fluvial/estuarine systems and in developing environmental management plans. Example 1 shows that when assessing nutrient behaviour in fluvial/estuarine depositional settings, it is important to examine the partitioning of phosphorus between grain size fractions to evaluate the sedimentological processes which control the dispersion and trapping of these contaminants. Example 2 shows that in studies of anthropogenic metal inputs to modern depositional settings, lateral and stratigraphic trends in sediment texture and mineralogy should be examined, in addition to trends in metal loads and evaluation of the prevailing physical, chemical and biological processes that may influence metal mobility and dispersion. Clearly, basic sedimentological data should form part of any assessment of potentially contaminated sites and part of investigations into the dispersion and trapping of contaminants in fluvial systems. These data are also required for rational environmental management to ensure that planning decisions are compatible with natural environmental constraints.

Flood susceptibility assessment in a highly urbanized alluvial fan: the case study of Sala Consilina (southern Italy

Directory of Open Access Journals (Sweden)

N. Santangelo

2011-10-01

Full Text Available This paper deals with the risk assessment to alluvial fan flooding at the piedmont zone of carbonate massifs of the southern Apennines chain (southern Italy. These areas are prime spots for urban development and are generally considered to be safer than the valley floors. As a result, villages and towns have been built on alluvial fans which, during intense storms, may be affected by flooding and/or debris flow processes.

The study area is located at the foothills of the Maddalena mountains, an elongated NW-SE trending ridge which bounds to the east the wide intermontane basin of Vallo di Diano. The area comprises a wide detrital talus (bajada made up by coalescent alluvial fans, ranging in age from the Middle Pleistocene to the Holocene. Historical analysis was carried out to ascertain the state of activity of the fans and to identify and map the zones most hit by past flooding. According to the information gathered, the Sala Consilina fans would appear prone to debris flows; in the past these processes have produced extensive damage and loss of life in the urban area. The watershed basins feeding the fans have very low response times and may produce debris flow events with high magnitudes. Taking into account the historical damage, the fan surface morphology, and the present urban development (street orientation and hydraulic network, the piedmont area was zoned and various susceptibility classes were detected. These results may represent a useful tool for studies aiming at territorial hazard mapping and civil protection interventions.

Relative Abundance and Diversity of Bacterial Methanotrophs at the Oxic?Anoxic Interface of the Congo Deep-Sea Fan

OpenAIRE

Bessette, Sandrine; Moalic, Yann; Gautey, S?bastien; Lesongeur, Fran?oise; Godfroy, Anne; Toffin, Laurent

2017-01-01

Sitting at ∼5,000 m water depth on the Congo-Angola margin and ∼760 km offshore of the West African coast, the recent lobe complex of the Congo deep-sea fan receives large amounts of fluvial sediments (3–5% organic carbon). This organic-rich sedimentation area harbors habitats with chemosynthetic communities similar to those of cold seeps. In this study, we investigated relative abundance, diversity and distribution of aerobic methane-oxidizing bacteria (MOB) communities at the oxic–anoxic in...

Costs and benefits of energy efficiency improvements in ceiling fans

Energy Technology Data Exchange (ETDEWEB)

Shah, Nihar; Sathaye, Nakul; Phadke, Amol; Letschert, Virginie [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technology Division

2013-10-15

Ceiling fans contribute significantly to residential electricity consumption, especially in developing countries with warm climates. The paper provides analysis of costs and benefits of several options to improve the efficiency of ceiling fans to assess the global potential for electricity savings and green house gas (GHG) emission reductions. Ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terawatt hours per year could be saved and 25 million metric tons of carbon dioxide equivalent (CO2-e) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize potential savings.

Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios

International Nuclear Information System (INIS)

Mouri, Goro

2015-01-01

For stream water, in which a relationship exists between wash-load concentration and discharge, an estimate of fine-sediment delivery may be obtained from a traditional fluvial wash-load rating curve. Here, we demonstrate that the remaining wash-load material load can be estimated from a traditional empirical principle on a nationwide scale. The traditional technique was applied to stream water for the whole of Japan. Four typical GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the following regional climate models to assess the wash-load component based on rating curves: the Model for Interdisciplinary Research on Climate (MIROC), the Meteorological Research Institute Atmospheric General Circulation Model (MRI-GCM), the Hadley Centre Global Environment Model (HadGEM) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model. The simulations consisted of an ensemble, including multiple physics configurations and different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5), which was used to produce monthly datasets for the whole country of Japan. The impacts of future climate changes on fluvial wash load in Japanese stream water were based on the balance of changes in hydrological factors. The annual and seasonal variations of the fluvial wash load were assessed from the result of the ensemble analysis in consideration of the Greenhouse Gas (GHG) emission scenarios. The determined results for the amount of wash load increase range from approximately 20 to 110% in the 2040s, especially along part of the Pacific Ocean and the Sea of Japan regions. In the 2090s, the amount of wash load is projected to increase by more than 50% over the whole of Japan. The assessment indicates that seasonal variation is particularly important because the rainy and typhoon seasons, which include extreme events, are the dominant seasons. Because fluvial wash-load-component turbidity

Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios

Energy Technology Data Exchange (ETDEWEB)

Mouri, Goro, E-mail: mouri@rainbow.iis.u-tokyo.ac.jp

2015-11-15

For stream water, in which a relationship exists between wash-load concentration and discharge, an estimate of fine-sediment delivery may be obtained from a traditional fluvial wash-load rating curve. Here, we demonstrate that the remaining wash-load material load can be estimated from a traditional empirical principle on a nationwide scale. The traditional technique was applied to stream water for the whole of Japan. Four typical GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the following regional climate models to assess the wash-load component based on rating curves: the Model for Interdisciplinary Research on Climate (MIROC), the Meteorological Research Institute Atmospheric General Circulation Model (MRI-GCM), the Hadley Centre Global Environment Model (HadGEM) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model. The simulations consisted of an ensemble, including multiple physics configurations and different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5), which was used to produce monthly datasets for the whole country of Japan. The impacts of future climate changes on fluvial wash load in Japanese stream water were based on the balance of changes in hydrological factors. The annual and seasonal variations of the fluvial wash load were assessed from the result of the ensemble analysis in consideration of the Greenhouse Gas (GHG) emission scenarios. The determined results for the amount of wash load increase range from approximately 20 to 110% in the 2040s, especially along part of the Pacific Ocean and the Sea of Japan regions. In the 2090s, the amount of wash load is projected to increase by more than 50% over the whole of Japan. The assessment indicates that seasonal variation is particularly important because the rainy and typhoon seasons, which include extreme events, are the dominant seasons. Because fluvial wash-load-component turbidity

Review: Bettina Fritzsche (2003. Pop-Fans. Studie einer Mädchenkultur [Pop-Fans: Study of a Girl Culture

Directory of Open Access Journals (Sweden)

Lothar Mikos

2006-05-01

Full Text Available This study focuses on the "girl culture" created by fans of boy groups and girl groups. The central case study is used to examine fan practices as cultural practices using reconstructive and documentary methodologies, and to assess the normative demands placed on young people. The study centers on the question of gender socialization by mediated symbolic resources, and shows that fan culture is a self-determined space in which girls can negotiate normative demands and engage with questions of gender, sexuality and the body, testing conformity and obstinacy. Fan activities are presented as part of the self-empowerment of girls. The study makes an important contribution to the research of a specific girl culture. It shows in a brilliant way how media representations are used as symbolic material in everyday cultural practices. URN: urn:nbn:de:0114-fqs0603187

Fluvial Apophenia

Science.gov (United States)

Coulthard, Tom; Armitage, John

2017-04-01

Apophenia describes the experience of seeing meaningful patterns or connections in random or meaningless data. Francis Bacon was one of the first to identify its role as a "human understanding is of its own nature prone to suppose the existence of more order and regularity in the world than it finds". Examples include pareidolia (seeing shapes in random patterns), gamblers fallacy (feeling past events alter probability), confirmation bias (bias to supporting a hypothesis rather than disproving), and he clustering illusion (an inability to recognise actual random data, instead believing there are patterns). Increasingly, researchers use records of past floods stored in sedimentary archives to make inferences about past environments, and to describe how climate and flooding may have changed. However, it is a seductive conclusion, to infer that drivers of landscape change can lead to changes in fluvial behaviour. Using past studies and computer simulations of river morphodynamics we explore how meaningful the link between drivers and fluvial changes is. Simple linear numerical models would suggest a direct relation between cause and effect, despite the potential for thresholds, phase changes, time-lags and damping. However, a comparatively small increase in model complexity (e.g. the Stream Power law) introducing non-linear behaviour and Increasing the complexity further can lead to the generation of time-dependent outputs despite constant forcing. We will use this range of findings to explore how apophenia may manifest itself in studies of fluvial systems, what this can mean and how we can try to account for it. Whilst discussed in the context of fluvial systems the concepts and inferences from this presentation are highly relevant to many other studies/disciplines.

Fluvial systems and their sedimentary models

Directory of Open Access Journals (Sweden)

Dragomir Skabeme

1995-12-01

Full Text Available The Slovenian géomorphologie and sedimentologie terminology for fluvial depositional environments is not established yet. Therefore a classification and the proposal for Slovenian names of fluvial sedimentary and erosional forms and influences controlling them are discussed. Attention is given to the problems of recognition of sedimentary environments in sedimentary rocks, and to fluvial sedimentary models.

Paleogeographic and Depositional Model for the Neogene fluvial succession, Pishin Belt Northwest Pakistan

DEFF Research Database (Denmark)

Kasi, Aimal Khan; Kassi, Akhtar Muhammad; Umar, Muhammad

2017-01-01

Miocene subaerial sedimentation started after the final closure of Katawaz Remnant Ocean. Based on detailed field data twelve facies were recognized in Neogene successions exposed in Pishin Belt. These facies were further organized into four facies associations i.e. channels, crevasse splay, natural levee...... and floodplain facies associations. Facies associations and variations provided ample evidences to recognize number of fluvial architectural components in the succession e.g., low-sinuosity sandy braided river, mixed-load meandering, high-sinuosity meandering channels, single-story sandstone and/or conglomerate...... channels, lateral accretion surfaces (point bars) and alluvial fans. Neogene sedimentation in the Pishin Belt was mainly controlled by active tectonism and thrusting in response to oblique collision of the Indian Plate with Afghan Block of the Eurasian Plate along the Chaman-Nushki Fault. Post Miocene...

Investigating selective transport and abrasion on an alluvial fan using quantitative grain size and shape analysis

Science.gov (United States)

Litwin, K. L.; Jerolmack, D. J.

2011-12-01

Selective sorting and abrasion are the two major fluvial processes that are attributed to the downstream fining of sediments in rivers and alluvial fans. Selective transport is the process by which smaller grains are preferentially transported downstream while larger grains are deposited closer to the source. Abrasion is defined by the production of fine sediments and sand that occurs by saltation of gravel, where particle-to-particle collisions supply the energy required to break apart grains. We hypothesize that abrasion results in the gradual fining of large grains and the production of fine sands and silts, while sorting accounts for the differences in transport of these two grain-size fractions produced from abrasion, thereby creating the abrupt gravel-sand transition observed in many channel systems. In this research, we explore both selective transport and abrasion processes on the Dog Canyon alluvial fan near Alamogordo, New Mexico. We complete an extensive grain size analysis down the main channel of the fan employing an image-based technique that utilizes an autocorrelation process. We also characterize changes in grain shape using standard shape parameters, as well as Fourier analysis, which allows the study of contributions of grain roughness on a variety of length scales. Sorting appears to dominate the upper portion of the fan; the grain-size distribution narrows moving downstream until reaching a point of equal mobility, at which point sorting ceases. Abrasion exerts a subtle but persistent effect on grains during transport down the fan. Shape analysis reveals that particles become more rounded by the removal of small-scale textural features, a process that is expected to only modestly influence grain size of gravel, but should produce significant quantities of sand. This study provides a better understanding of the importance of grain abrasion and sorting on the downstream fining of channel grains in an alluvial fan, as well as an improved knowledge

Precautions against axial fan stall in reactor building to Tianwan NPP

International Nuclear Information System (INIS)

Liu Chunlong; Pei Junmin

2011-01-01

The paper introduces the mechanism and harm of rotating stall of axial fans, analyzes the necessity for prevention against axial fan stall in reactor building of Tianwan NPP, introduces the precautions, and then makes an assessment on anti-stall effect of flow separators. It can provide reference for model-selection or reconstruction of similar fans in power stations, and for operation and maintenance of axial fans. (authors)

Advance Noise Control Fan II: Test Rig Fan Risk Management Study

Science.gov (United States)

Lucero, John

2013-01-01

Since 1995 the Advanced Noise Control Fan (ANCF) has significantly contributed to the advancement of the understanding of the physics of fan tonal noise generation. The 9'x15' WT has successfully tested multiple high speed fan designs over the last several decades. This advanced several tone noise reduction concepts to higher TRL and the validation of fan tone noise prediction codes.

Analysis of dynamic parameters of mine fans

Science.gov (United States)

Russky, E. Yu

2018-03-01

The design of the rotor of an axial fan and its main units, namely double leaf blades impeller and the main shaft are discussed. The parameters of a disturbed mine air flow under sudden outbursts are determined and the influence of disturbances on frequencies of axial fan units is assessed. The scope of the assessment embraces the disturbance effect on the blades and on the torsional vibrations of the main shafts. The dependences of the stresses in the elements of the rotor versus the disturbed air flow parameters are derived.

Geomorphic Unit Tool (GUT): Applications of Fluvial Mapping

Science.gov (United States)

Kramer, N.; Bangen, S. G.; Wheaton, J. M.; Bouwes, N.; Wall, E.; Saunders, C.; Bennett, S.; Fortney, S.

2017-12-01

Geomorphic units are the building blocks of rivers and represent distinct habitat patches for many fluvial organisms. We present the Geomorphic Unit Toolkit (GUT), a flexible GIS geomorphic unit mapping tool, to generate maps of fluvial landforms from topography. GUT applies attributes to landforms based on flow stage (Tier 1), topographic signatures (Tier 2), geomorphic characteristics (Tier 3) and patch characteristics (Tier 4) to derive attributed maps at the level of detail required by analysts. We hypothesize that if more rigorous and consistent geomorphic mapping is conducted, better correlations between physical habitat units and ecohydraulic model results will be obtained compared to past work. Using output from GUT for coarse bed tributary streams in the Columbia River Basin, we explore relationships between salmonid habitat and geomorphic spatial metrics. We also highlight case studies of how GUT can be used to showcase geomorphic impact from large wood restoration efforts. Provided high resolution topography exists, this tool can be used to quickly assess changes in fluvial geomorphology in watersheds impacted by human activities.

Two novel genes, fanA and fanB, involved in the biogenesis of K99 fimbriae.

Science.gov (United States)

Roosendaal, E; Boots, M; de Graaf, F K

1987-08-11

The nucleotide sequence of the region located transcriptionally upstream of the K99 fimbrial subunit gene (fanC) was determined. Several putative transcription signals and two open reading frames, designated fanA and fanB, became apparent. Frameshift mutations in fanA and fanB reduced K99 fimbriae expression 8-fold and 16-fold, respectively. Complementation of the mutants in trans restored the K99 expression to about 75% of the wild type level, indicating that fanA and fanB code for transacting polypeptides involved in the biogenesis of K99 fimbriae. The fanA and fanB gene products FanA and FanB were not detectable in minicell preparations, indicating that both polypeptides are synthesized in very small amounts. However, in an in vitro DNA directed translation system FanA and FanB could be identified. The deduced amino acid sequences of FanA and FanB showed that both polypeptides contain no signal peptides, indicating a cytoplasmic location. Furthermore, the polypeptides are very hydrophilic, mainly basic, and exhibit remarkable homology to each other and to a regulatory protein (papB) encoded by the pap-operon (1). Some of these features are characteristics of nucleic acid binding proteins, which suggests that FanA and FanB have a regulatory function in the synthesis of FanC and the auxiliary polypeptides FanD-H.

The Gediz River fluvial archive

NARCIS (Netherlands)

Maddy, D.; Veldkamp, A.; Demir, T.; Gorp, van W.; Wijbrans, J.R.; Hinsbergen, van D.J.J.; Dekkers, M.J.; Schreve, D.; Schoorl, J.M.; Scaife, R.

2017-01-01

The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River

WHO ARE FANS OF FACEBOOK FAN PAGES? AN ELECTRONIC WORD-OF-MOUTH COMMUNICATION PERSPECTIVE

Directory of Open Access Journals (Sweden)

Xiao Hu

2014-12-01

Full Text Available Given its great business value and popularity, Facebook fan pages have attracted more and more attention in both industry and academia. Fans of Facebook fan pages play an important role in electronic word-of-mouth (eWOM communication. This study focused on the population of fans on Facebook fan pages and examined the differences between fans and non-fans in terms of demographics, social network sites (SNS use, Internet use, and online shopping behaviors. The results indicated that fans used SNS more frequently than non-fans. Additionally, from the eWOM perspective, the researchers moderated product types in the model of people’s word-of-mouth (WOM preferences and found that people had different preferences for eWOM and traditional WOM for different products. Traditional WOM is still the most important source of information for people when shopping online.

Contrasting morphodynamics in alluvial fans and fan deltas: effect of the downstream boundary

NARCIS (Netherlands)

Dijk, M. van; Kleinhans, M.G.; Postma, G.; Kraal, E.

2012-01-01

Alluvial fans and fan deltas can, in principle, have exactly the same upstream conditions, but fan deltas by definition have ponding water at their downstream boundary. This ponding creates effects on the autogenic behaviour of fan deltas, such as backwater adaptation, mouth bars and backward

Intrinsic stream-capture control of stepped fan pediments in the High Atlas piedmont of Ouarzazate (Morocco)

Science.gov (United States)

Pastor, A.; Babault, J.; Teixell, A.; Arboleya, M. L.

2012-11-01

The Ouarzazate basin is a Cenozoic foreland basin located to the south of the High Atlas Mountains. The basin has been externally drained during the Quaternary, with fluvial dynamics dominated by erosive processes from a progressive base level drop. The current drainage network is composed of rivers draining the mountain and carrying large amounts of coarse sediments and by piedmont streams with smaller catchments eroding the soft Cenozoic rocks of the Ouarzazate basin. The coarse-grained sediments covering the channel beds of main rivers cause the steepening of the channel gradient and act as a shield inhibiting bedrock incision. Under such circumstances, piedmont streams that incise to lower gradients evolve to large, depressed pediments at lower elevations and threaten to capture rivers originating in the mountain. Much of the current surface of the Ouarzazate basin is covered by coarse sediments forming large systems of stepped fan pediments that developed by the filling of low elevation pediments after a capture event. We identified 14 capture events, and previously published geochronology support an ~ 100 ka frequency for fan pediment formation. Our study indicates that the reorganization of the fluvial network in the Ouarzazate basin during the late Pleistocene and Holocene has been controlled by the piedmont-stream piracy process, a process ultimately controlled by the cover effect. The stream capture is influenced by erosion, sediment supply and transport, and therefore may not be entirely decoupled from tectonic and climatic forcing. Indeed, we show that at least two capture events may have occurred during climate changes, and local tectonic structures control at most the spatial localization of capture events.

Computational Aerodynamic Simulations of an 840 ft/sec Tip Speed Advanced Ducted Propulsor Fan System Model for Acoustic Methods Assessment and Development

Science.gov (United States)

Tweedt, Daniel L.

2014-01-01

Computational Aerodynamic simulations of an 840 ft/sec tip speed, Advanced Ducted Propulsor fan system were performed at five different operating points on the fan operating line, in order to provide detailed internal flow field information for use with fan acoustic prediction methods presently being developed, assessed and validated. The fan system is a sub-scale, lownoise research fan/nacelle model that has undergone extensive experimental testing in the 9- by 15- foot Low Speed Wind Tunnel at the NASA Glenn Research Center, resulting in quality, detailed aerodynamic and acoustic measurement data. Details of the fan geometry, the computational fluid dynamics methods, the computational grids, and various computational parameters relevant to the numerical simulations are discussed. Flow field results for three of the five operating conditions simulated are presented in order to provide a representative look at the computed solutions. Each of the five fan aerodynamic simulations involved the entire fan system, excluding a long core duct section downstream of the core inlet guide vane. As a result, only fan rotational speed and system bypass ratio, set by specifying static pressure downstream of the core inlet guide vane row, were adjusted in order to set the fan operating point, leading to operating points that lie on a fan operating line and making mass flow rate a fully dependent parameter. The resulting mass flow rates are in good agreement with measurement values. The computed blade row flow fields for all five fan operating points are, in general, aerodynamically healthy. Rotor blade and fan exit guide vane flow characteristics are good, including incidence and deviation angles, chordwise static pressure distributions, blade surface boundary layers, secondary flow structures, and blade wakes. Examination of the computed flow fields reveals no excessive boundary layer separations or related secondary-flow problems. A few spanwise comparisons between

Computational Aerodynamic Simulations of a 1484 ft/sec Tip Speed Quiet High-Speed Fan System Model for Acoustic Methods Assessment and Development

Science.gov (United States)

Tweedt, Daniel L.

2014-01-01

Computational Aerodynamic simulations of a 1484 ft/sec tip speed quiet high-speed fan system were performed at five different operating points on the fan operating line, in order to provide detailed internal flow field information for use with fan acoustic prediction methods presently being developed, assessed and validated. The fan system is a sub-scale, low-noise research fan/nacelle model that has undergone experimental testing in the 9- by 15-foot Low Speed Wind Tunnel at the NASA Glenn Research Center. Details of the fan geometry, the computational fluid dynamics methods, the computational grids, and various computational parameters relevant to the numerical simulations are discussed. Flow field results for three of the five operating points simulated are presented in order to provide a representative look at the computed solutions. Each of the five fan aerodynamic simulations involved the entire fan system, which includes a core duct and a bypass duct that merge upstream of the fan system nozzle. As a result, only fan rotational speed and the system bypass ratio, set by means of a translating nozzle plug, were adjusted in order to set the fan operating point, leading to operating points that lie on a fan operating line and making mass flow rate a fully dependent parameter. The resulting mass flow rates are in good agreement with measurement values. Computed blade row flow fields at all fan operating points are, in general, aerodynamically healthy. Rotor blade and fan exit guide vane flow characteristics are good, including incidence and deviation angles, chordwise static pressure distributions, blade surface boundary layers, secondary flow structures, and blade wakes. Examination of the computed flow fields reveals no excessive or critical boundary layer separations or related secondary-flow problems, with the exception of the hub boundary layer at the core duct entrance. At that location a significant flow separation is present. The region of local flow

Assessing the Effects of Climate on Global Fluvial Discharge Variability

Science.gov (United States)

Hansford, M. R.; Plink-Bjorklund, P.

2017-12-01

Plink-Bjorklund (2015) established the link between precipitation seasonality and river discharge variability in the monsoon domain and subtropical rivers (see also Leier et al, 2005; Fielding et al., 2009), resulting in distinct morphodynamic processes and a sedimentary record distinct from perennial precipitation zone in tropical rainforest zone and mid latitudes. This study further develops our understanding of discharge variability using a modern global river database created with data from the Global Runoff Data Centre (GRDC). The database consists of daily discharge for 595 river stations and examines them using a series of discharge variability indexes (DVI) on different temporal scales to examine how discharge variability occurs in river systems around the globe. These indexes examine discharge of individual days and monthly averages that allows for comparison of river systems against each other, regardless of size of the river. Comparing river discharge patterns in seven climate zones (arid, cold, humid subtropics, monsoonal, polar, rainforest, and temperate) based off the Koppen-Geiger climate classifications reveals a first order climatic control on discharge patterns and correspondingly sediment transport. Four groupings of discharge patterns emerge when coming climate zones and DVI: persistent, moderate, seasonal, and erratic. This dataset has incredible predictive power about the nature of discharge in fluvial systems around the world. These seasonal effects on surface water supply affects river morphodynamics and sedimentation on a wide timeframe, ranging from large single events to an inter-annual or even decadal timeframe. The resulting sedimentary deposits lead to differences in fluvial architecture on a range of depositional scales from sedimentary structures and bedforms to channel complex systems. These differences are important to accurately model for several reasons, ranging from stratigraphic and paleoenviromental reconstructions to more

Assessment of spatiotemporal variations in the fluvial wash-load component in the 21st century with regard to GCM climate change scenarios.

Science.gov (United States)

Mouri, Goro

2015-11-15

For stream water, in which a relationship exists between wash-load concentration and discharge, an estimate of fine-sediment delivery may be obtained from a traditional fluvial wash-load rating curve. Here, we demonstrate that the remaining wash-load material load can be estimated from a traditional empirical principle on a nationwide scale. The traditional technique was applied to stream water for the whole of Japan. Four typical GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the following regional climate models to assess the wash-load component based on rating curves: the Model for Interdisciplinary Research on Climate (MIROC), the Meteorological Research Institute Atmospheric General Circulation Model (MRI-GCM), the Hadley Centre Global Environment Model (HadGEM) and the Geophysical Fluid Dynamics Laboratory (GFDL) climate model. The simulations consisted of an ensemble, including multiple physics configurations and different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5), which was used to produce monthly datasets for the whole country of Japan. The impacts of future climate changes on fluvial wash load in Japanese stream water were based on the balance of changes in hydrological factors. The annual and seasonal variations of the fluvial wash load were assessed from the result of the ensemble analysis in consideration of the Greenhouse Gas (GHG) emission scenarios. The determined results for the amount of wash load increase range from approximately 20 to 110% in the 2040s, especially along part of the Pacific Ocean and the Sea of Japan regions. In the 2090s, the amount of wash load is projected to increase by more than 50% over the whole of Japan. The assessment indicates that seasonal variation is particularly important because the rainy and typhoon seasons, which include extreme events, are the dominant seasons. Because fluvial wash-load-component turbidity

75 FR 79952 - Airworthiness Directives; DASSAULT AVIATION Model Falcon 10 Airplanes; Model FAN JET FALCON, FAN...

Science.gov (United States)

2010-12-21

... Airworthiness Directives; DASSAULT AVIATION Model Falcon 10 Airplanes; Model FAN JET FALCON, FAN JET FALCON.... (1) DASSAULT AVIATION Model Falcon 10 airplanes, Model FAN JET FALCON, FAN JET FALCON SERIES C, D, E... airplanes Inspection threshold (whichever occurs later) Inspection interval Model FAN JET FALCON, FAN JET...

A non-regular Groebner fan

OpenAIRE

Jensen, Anders N.

2005-01-01

The Groebner fan of an ideal $I\\subset k[x_1,...,x_n]$, defined by Mora and Robbiano, is a complex of polyhedral cones in $R^n$. The maximal cones of the fan are in bijection with the distinct monomial initial ideals of $I$ as the term order varies. If $I$ is homogeneous the Groebner fan is complete and is the normal fan of the state polytope of $I$. In general the Groebner fan is not complete and therefore not the normal fan of a polytope. We may ask if the restricted Groebner fan, a subdivi...

Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States

Energy Technology Data Exchange (ETDEWEB)

Cole, E.L.; Fowler, M.L.; Jackson, S.R.; Madden, M.P.; Raw-Schatzinger, V.; Salamy, S.P.; Sarathi, P.; Young, M.A.

1999-04-28

The Department of Energy's (DOE's) Oil Recovery Field Demonstration Program was initiated in 1992 to maximize the economically and environmentally sound recovery of oil from known domestic reservoirs and to preserve access to this resource. Cost-shared field demonstration projects are being initiated in geology defined reservoir classes which have been prioritized by their potential for incremental recovery and their risk of abandonment. This document defines the characteristics of the fifth geological reservoir class in the series, fluvial/alluvial reservoirs. The reservoirs of Class 5 include deposits of alluvial fans, braided streams, and meandering streams. Deposit morphologies vary as a complex function of climate and tectonics and are characterized by a high degree of heterogeneity to fluid flow as a result of extreme variations in water energy as the deposits formed.

Controls on alluvial fans morphology

Science.gov (United States)

Delorme, P.; Devauchelle, O.; Lajeunesse, E.; Barrier, L.; Métivier, F.

2017-12-01

Using laboratory experiments, we investigate the influence of water and sediment discharges on the morphology of an alluvial fan. In our flume, a single-thread laminar river deposits corundum sand (0.4 mm) into a conical fan. We record the fan progradation with top-view images, and measure its shape using the deformation of a Moiré pattern. The fan remains virtually self-affine as it grows, with a nearly constant slope. We find that, when the sediment discharge is small, the longitudinal slope of the fan remains close to that of a river at the threshold for sediment transport. A higher sediment discharge causes the fan's slope to depart from the threshold value. Due to the downstream decrease of the sediment load, this slope gets shallower towards the fan's toe. This mechanism generates a slightly concave fan profile. This suggests that the proximal slope of an alluvial fan could be a proxy for the sediment flux that feeds the fan.Finally, we discuss the applicability of these results to natural systems.

Assessment of the dental and skeletal effects of fan-type rapid maxillary expansion screw and Hyrax screw on craniofacial structures

Directory of Open Access Journals (Sweden)

Umarevathi Gopalakrishnan

2017-01-01

Full Text Available Aims and Objectives: The purpose of the study was to assess the skeletal and dental effects of fan-type rapid maxillary expansion (RME appliance and Hyrax RME appliance on the craniofacial structures. Materials and Methods: The sample of the study included 12 patients with constricted maxillary arches. Acrylic bonded type of attachment was used for both groups. Changes in sagittal, vertical, and transverse relationship were assessed with lateral and frontal cephalograms, respectively. Intercanine and intermolar widths were measured with stone models. Pre- and immediate post-treatment records were statistically analyzed with Wilcoxon signed-rank test. The differences between the groups were evaluated using Mann–Whitney U-test. Since the data pertaining to intercanine width and intermolar width were normally distributed, parametric test of signifi cance (unpaired t-test was used to compare them. Results: Results showed that Hyrax presented with signifi cantly greater increments for both nasal cavity width and maxillary width when compared to fan-type RME. Both groups had retroclination of incisors. The increase in the intercanine width was almost similar in both groups. Conclusion: Fan-type RME caused only minimal expansion of the intermolar width when compared to the Hyrax. The ratio between the intercanine and intermolar width expansion was nearly 4:1 in the fan-type RME and 0.75:1 in Hyrax.

Assessing Fan Flutter Stability in the Presence of Inlet Distortion Using One-way and Two-way Coupled Methods

Science.gov (United States)

Herrick, Gregory P.

2014-01-01

Concerns regarding noise, propulsive efficiency, and fuel burn are inspiring aircraft designs wherein the propulsive turbomachines are partially (or fully)embedded within the airframe; such designs present serious concerns with regard to aerodynamic and aeromechanic performance of the compression system in response to inlet distortion. Previously, a preliminary design of a forward-swept high-speed fan exhibited flutter concerns in clean-inlet flows, and the present author then studied this fan further in the presence of off-design distorted in-flows. A three-dimensional, unsteady, Navier-Stokes computational fluid dynamics code is applied to analyze and corroborate fan performance with clean inlet flow. This code, already validated in its application to assess aerodynamic damping of vibrating blades at various flow conditions using a loosely-coupled approach, is modified to include a tightly-coupled aeroelastic simulation capability, and then loosely-coupled and tightly-coupled methods arecompared in their evaluation of flutter stability in distorted in-flows.

Highstand shelf fans: The role of buoyancy reversal in the deposition of a new type of shelf sand body

Science.gov (United States)

Steel, Elisabeth; Simms, Alexander R.; Warrick, Jonathan; Yokoyama, Yusuke

2016-01-01

Although sea-level highstands are typically associated with sediment-starved continental shelves, high sea level does not hinder major river floods. Turbidity currents generated by plunging of sediment-laden rivers at the fluvial-marine interface, known as hyperpycnal flows, allow for cross-shelf transport of suspended sand beyond the coastline. Hyperpycnal flows in southern California have deposited six subaqueous fans on the shelf of the northern Santa Barbara Channel in the Holocene. Using eight cores and nine grab samples, we describe the deposits, age, and stratigraphic architecture of two fans in the Santa Barbara Channel. Fan lobes have up to 3 m of relief and are composed of multiple hyperpycnite beds ∼5 cm to 40 cm thick. Deposit architecture and geometry suggest the hyperpycnal flows became positively buoyant and lifted off the seabed, resulting in well-sorted, structureless, elongate sand lobes. Contrary to conventional sequence stratigraphic models, the presence of these features on the continental shelf suggests that active-margin shelves may locally develop high-quality reservoir sand bodies during sea-level highstands, and that such shelves need not be solely the site of sediment bypass. These deposits may provide a Quaternary analogue to many well-sorted sand bodies in the rock record that are interpreted as turbidites but lack typical Bouma-type features.

Assessing Fan Flutter Stability in Presence of Inlet Distortion Using One-Way and Two-Way Coupled Methods

Science.gov (United States)

Herrick, Gregory P.

2014-01-01

Concerns regarding noise, propulsive efficiency, and fuel burn are inspiring aircraft designs wherein the propulsive turbomachines are partially (or fully) embedded within the airframe; such designs present serious concerns with regard to aerodynamic and aeromechanic performance of the compression system in response to inlet distortion. Previously, a preliminary design of a forward-swept high-speed fan exhibited flutter concerns in clean-inlet flows, and the present author then studied this fan further in the presence of off-design distorted in-flows. Continuing this research, a three-dimensional, unsteady, Navier-Stokes computational fluid dynamics code is again applied to analyze and corroborate fan performance with clean inlet flow and now with a simplified, sinusoidal distortion of total pressure at the aerodynamic interface plane. This code, already validated in its application to assess aerodynamic damping of vibrating blades at various flow conditions using a one-way coupled energy-exchange approach, is modified to include a two-way coupled timemarching aeroelastic simulation capability. The two coupling methods are compared in their evaluation of flutter stability in the presence of distorted in-flows.

Climate induced changes in the circulation and dispersal patterns of the fluvial sources during late Quaternary in the middle Bengal Fan

Digital Repository Service at National Institute of Oceanography (India)

Chauhan, O.S.; Vogelsang, E.

From a transact along 15˚N latitude in the middle Bengal Fan, temporal and spatial variations in the granulometric parameters and clay minerals in 14C dated box cores from the eastern, the central and the western regions were studied to determine...

Braidplain, floodplain and playa lake, alluvial-fan, aeolian and palaeosol facies composing a diversified lithogenetical sequence in the permian and triassic of South Devon (England)

Science.gov (United States)

Mader, Detlef

The Permian and Triassic of South Devon (England) are a continental red bed sequence of very diversified lithogenetical composition. Within the thick series, the distribution of the main depositional environments being fluvial braidplain, fluvial floodplain and playa lake, alluvial fan, aeolian dune and calcrete palaeosol changes repeatedly in both horizontal and vertical direction. Significant sedimentary milieus such as aeolian dunes and calcrete palaeosols occur repeatedly within the succession, but are also lacking in several parts of the sequence. Fluvial braidplain deposits comprise conglomerates, sandstones, intraformational reworking horizons and mudstones and originate in channels and overbank plains of a braided river system. Conglomerates and sandstones are formed by migration of bars and spreading out of sheets during infilling of streams and aggradation of flats. Gravel is often enriched as lag pockets or veneers within steeper scour holes and kolk pots or on the plane floor of the watercourse. Finer-grained sandstones and mudstones are laid down by suspension settling in stagnant water bodies such as small lakes in the overbank area and residual pools in interbar depressions during low-stage or waning-flow in active channels or in abandoned streams. Spectacular bioturbation features in some sandstones with both horizontal tubes and vertical burrows testify to the colonization of the sediments at the bottom of the rivers with declining discharge and transport capacity. Intraformational reworking horizons with ghost-like remnants of degraded sandstones, mudstones and pedogenic carbonates document partially severe condensation of the sequence by removal of some facies elements from the depositional record. The occasionally occurring gravel-bearing mudstones or silty-clayey sandstones represent products of high-energy water surges overspilling the channel banks and transporting sandy and gravelly bed-load in limited amounts beyond the levee wall. The

Active Vibration Reduction of Titanium Alloy Fan Blades (FAN1) Using Piezoelectric Materials

Science.gov (United States)

Choi, Benjamin; Kauffman, Jeffrey; Duffy, Kirsten; Provenza, Andrew; Morrison, Carlos

2010-01-01

The NASA Glenn Research Center is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this paper, a digital resonant control technique emulating passive shunt circuits is used to demonstrate vibration reduction of FAN1 Ti real fan blade at the several target modes. Single-mode control and multi-mode control using one piezoelectric material are demonstrated. Also a conceptual study of how to implement this digital control system into the rotating fan blade is discussed.

Online Fan Practices and CALL

Science.gov (United States)

Sauro, Shannon

2017-01-01

This article provides a narrative overview of research on online fan practices for language and literacy learning, use, and identity work. I begin with an introduction to online fan communities and common fan practices found in these online affinity spaces, the best known of which is fan fiction, fictional writing that reinterprets and remixes the…

75 FR 43878 - Airworthiness Directives; DASSAULT AVIATION Model Falcon 10 Airplanes; Model FAN JET FALCON, FAN...

Science.gov (United States)

2010-07-27

... Model Falcon 10 Airplanes; Model FAN JET FALCON, FAN JET FALCON SERIES C, D, E, F, and G Airplanes.... Since that NPRM was issued, we have determined that Model FAN JET FALCON SERIES C, D, E, F, and G..., Model FAN JET FALCON, FAN JET FALCON SERIES C, D, E, F, and G airplanes, and Model MYSTERE-FALCON 20-C5...

Aeolian and fluvial processes in dryland regions: the need for integrated studies

Science.gov (United States)

Belnap, Jayne; Munson, Seth M.; Field, Jason P.

2011-01-01

Aeolian and fluvial processes play a fundamental role in dryland regions of the world and have important environmental and ecological consequences from local to global scales. Although both processes operate over similar spatial and temporal scales and are likely strongly coupled in many dryland systems, aeolian and fluvial processes have traditionally been studied separately, making it difficult to assess their relative importance in drylands, as well as their potential for synergistic interaction. Land degradation by accelerated wind and water erosion is a major problem throughout the world's drylands, and although recent studies suggest that these processes likely interact across broad spatial and temporal scales to amplify the transport of soil resources from and within drylands, many researchers and land managers continue to view them as separate and unrelated processes. Here, we illustrate how aeolian and fluvial sediment transport is coupled at multiple spatial and temporal scales and highlight the need for these interrelated processes to be studied from a more integrated perspective that crosses traditional disciplinary boundaries. Special attention is given to how the growing threat of climate change and land-use disturbance will influence linkages between aeolian and fluvial processes in the future. We also present emerging directions for interdisciplinary needs within the aeolian and fluvial research communities that call for better integration across a broad range of traditional disciplines such as ecology, biogeochemistry, agronomy, and soil conservation.

Comparison of BacT/Alert FAN and FAN Plus Bottles with Conventional Medium for Culturing Cerebrospinal Fluid.

Science.gov (United States)

Yoo, In Young; Chun, Sejong; Song, Dong Joon; Huh, Hee Jae; Lee, Nam Yong

2016-11-01

We compared the BacT/Alert system FAN and FAN Plus media to conventional media for culturing cerebrospinal fluid (CSF) with 2,545 samples. FAN/FAN Plus bottles showed better performance for isolating microorganisms in CSF than conventional media (positive rate, 7.2% [182/2,545] versus 3.1% [80/2,545]). The incremental recovery rate of Cryptococcus neoformans from FAN Plus bottles was higher than that from FAN bottles. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Industrial fans used in nuclear facilities

International Nuclear Information System (INIS)

Carlson, J.A.

1987-01-01

Industrial fans are widely used in nuclear facilities, and their most common use is in building ventilation. To control the spread of contamination, airflows are maintained at high levels. Therefore, the selection of the fan and fan control are important to the safety of people, equipment and the environment. As a result, 80% of all energy used in nuclear facilities is fan energy. Safety evolves from the durability, control and redundancy in the system. In new or retrofit installations, testing and qualification of fans and systems are completed prior to start-up. Less important but necessary is the energy conservation aspect of fan selection and installations. Fan efficiency, type of control and system installation are evaluated for energy use

Observational Analysis of Coronal Fans

Science.gov (United States)

Talpeanu, D.-C.; Rachmeler, L; Mierla, Marilena

2017-01-01

Coronal fans (see Figure 1) are bright observational structures that extend to large distances above the solar surface and can easily be seen in EUV (174 angstrom) above the limb. They have a very long lifetime and can live up to several Carrington rotations (CR), remaining relatively stationary for many months. Note that they are not off-limb manifestation of similarly-named active region fans. The solar conditions required to create coronal fans are not well understood. The goal of this research was to find as many associations as possible of coronal fans with other solar features and to gain a better understanding of these structures. Therefore, we analyzed many fans and created an overview of their properties. We present the results of this statistical analysis and also a case study on the longest living fan.

The Fan Effect Co-production, Communication & Dispute Between Digital Game Fans, Developers and Publishers

OpenAIRE

Jalamo, Tuomas

2016-01-01

This study analyses the relationship between video game fans, developers and publishers. The topic is approached via a case study that explores online fan reviews of the video game Mass Effect 3 at the Metacritic website. The game had a controversial ending, which was posthumously altered due to negative feedback from the fans. The study seeks to understand the ways in which the case study reflects the issues between the fans and the industry and how these themes are related to the wider disc...

Pump and Fan Technology Characterization and R&D Assessment

Energy Technology Data Exchange (ETDEWEB)

Goetzler, William [Navigant Consulting, Burlington, MA (United States); Guernsey, Matt [Navigant Consulting, Burlington, MA (United States); Chung, Greg [Navigant Consulting, Burlington, MA (United States)

2015-10-01

This report provides the Building Technologies Office (BTO) and the research and development (R&D) community with a technical and market analysis of pumps and fans as they pertain to commercial and residential buildings as well as key conclusions regarding the R&D opportunities that can help achieve BTO’s energy savings goals.

30 CFR 57.4504 - Fan installations.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fan installations. 57.4504 Section 57.4504... Control Installation/construction/maintenance § 57.4504 Fan installations. (a) Fan houses, fan bulkheads... of combustible materials, except installed wiring, ground and track support, headframes, and direct...

Fluvial geomorphology on Earth-like planetary surfaces: A review.

Science.gov (United States)

Baker, Victor R; Hamilton, Christopher W; Burr, Devon M; Gulick, Virginia C; Komatsu, Goro; Luo, Wei; Rice, James W; Rodriguez, J A P

2015-09-15

Morphological evidence for ancient channelized flows (fluvial and fluvial-like landforms) exists on the surfaces of all of the inner planets and on some of the satellites of the Solar System. In some cases, the relevant fluid flows are related to a planetary evolution that involves the global cycling of a volatile component (water for Earth and Mars; methane for Saturn's moon Titan). In other cases, as on Mercury, Venus, Earth's moon, and Jupiter's moon Io, the flows were of highly fluid lava. The discovery, in 1972, of what are now known to be fluvial channels and valleys on Mars sparked a major controversy over the role of water in shaping the surface of that planet. The recognition of the fluvial character of these features has opened unresolved fundamental questions about the geological history of water on Mars, including the presence of an ancient ocean and the operation of a hydrological cycle during the earliest phases of planetary history. Other fundamental questions posed by fluvial and fluvial-like features on planetary bodies include the possible erosive action of large-scale outpourings of very fluid lavas, such as those that may have produced the remarkable canali forms on Venus; the ability of exotic fluids, such as methane, to create fluvial-like landforms, as observed on Saturn's moon, Titan; and the nature of sedimentation and erosion under different conditions of planetary surface gravity. Planetary fluvial geomorphology also illustrates fundamental epistemological and methodological issues, including the role of analogy in geomorphological/geological inquiry.

RUO-FAN QIU

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics. RUO-FAN QIU. Articles written in Pramana – Journal of Physics. Volume 89 Issue 6 December 2017 pp 81 Research Article. Three-dimensional coupled double-distribution-function lattice Boltzmann models for compressible Navier–Stokes equations · RUO-FAN QIU ...

Titan's fluvial valleys: Morphology, distribution, and spectral properties

Science.gov (United States)

Langhans, M.H.; Jaumann, R.; Stephan, K.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Baines, K.H.; Nicholson, P.D.; Lorenz, R.D.; Soderblom, L.A.; Soderblom, J.M.; Sotin, Christophe; Barnes, J.W.; Nelson, R.

2012-01-01

Titan's fluvial channels have been investigated based on data obtained by the Synthetic Aperture Radar (SAR) instrument and the Visible and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft. In this paper, a database of fluvial features is created based on radar-SAR data aiming to unveil the distribution and the morphologic and spectral characteristics of valleys on Titan on a global scale. It will also study the spatial relations between fluvial valleys and Titan's geologic units and spectral surface units which have become accessible thanks to Cassini-VIMS data. Several distinct morphologic types of fluvial valleys can be discerned by SAR-images. Dendritic valley networks appear to have much in common with terrestrial dendritic systems owing to a hierarchical and tree-shaped arrangement of the tributaries which is indicative of an origin from precipitation. Dry valleys constitute another class of valleys resembling terrestrial wadis, an indication of episodic and strong flow events. Other valley types, such as putative canyons, cannot be correlated with rainfall based on their morphology alone, since it cannot be ruled out that they may have originated from volcanic/tectonic action or groundwater sapping. Highly developed and complex fluvial networks with channel lengths of up to 1200 km and widths of up to 10 km are concentrated only at a few locations whereas single valleys are scattered over all latitudes. Fluvial valleys are frequently found in mountainous areas. Some terrains, such as equatorial dune fields and undifferentiated plains at mid-latitudes, are almost entirely free of valleys. Spectrally, fluvial terrains are often characterized by a high reflectance in each of Titan's atmospheric windows, as most of them are located on Titan's bright 'continents'. Nevertheless, valleys are spatially associated with a surface unit appearing blue due to its higher reflection at 1.3??m in a VIMS false color RGB composite with R: 1.59/1.27??m, G: 2

Low Noise Research Fan Stage Design

Science.gov (United States)

Hobbs, David E.; Neubert, Robert J.; Malmborg, Eric W.; Philbrick, Daniel H.; Spear, David A.

1995-01-01

This report describes the design of a Low Noise ADP Research Fan stage. The fan is a variable pitch design which is designed at the cruise pitch condition. Relative to the cruise setting, the blade is closed at takeoff and opened for reverse thrust operation. The fan stage is a split flow design with fan exit guide vanes and core stators. This fan stage design was combined with a nacelle and engine core duct to form a powered fan/nacelle, subscale model. This model is intended for use in aerodynamic performance, acoustic and structural testing in a wind tunnel. The model has a 22-inch outer fan diameter and a hub-to-top ratio of 0.426 which permits the use of existing NASA fan and cowl force balance designs and rig drive system. The design parameters were selected to permit valid acoustic and aerodynamic comparisons with the PW 17-inch rig previously tested under NASA contract. The fan stage design is described in detail. The results of the design axisymmetric analysis at aerodynamic design condition are included. The structural analysis of the fan rotor and attachment is described including the material selections and stress analysis. The blade and attachment are predicted to have adequate low cycle fatigue life, and an acceptable operating range without resonant stress or flutter. The stage was acoustically designed with airfoil counts in the fan exit guide vane and core stator to minimize noise. A fan-FEGV tone analysis developed separately under NASA contract was used to determine these airfoil counts. The fan stage design was matched to a nacelle design to form a fan/nacelle model for wind tunnel testing. The nacelle design was developed under a separate NASA contract. The nacelle was designed with an axisymmetric inlet, cowl and nozzle for convenience in testing and fabrication. Aerodynamic analysis of the nacelle confirmed the required performance at various aircraft operating conditions.

Impeller Design of a Centrifugal Fan with Blade Optimization

Directory of Open Access Journals (Sweden)

Yu-Tai Lee

2011-01-01

Full Text Available A method is presented for redesigning a centrifugal impeller and its inlet duct. The double-discharge volute casing is a structural constraint and is maintained for its shape. The redesign effort was geared towards meeting the design volute exit pressure while reducing the power required to operate the fan. Given the high performance of the baseline impeller, the redesign adopted a high-fidelity CFD-based computational approach capable of accounting for all aerodynamic losses. The present effort utilized a numerical optimization with experiential steering techniques to redesign the fan blades, inlet duct, and shroud of the impeller. The resulting flow path modifications not only met the pressure requirement, but also reduced the fan power by 8.8% over the baseline. A refined CFD assessment of the impeller/volute coupling and the gap between the stationary duct and the rotating shroud revealed a reduction in efficiency due to the volute and the gap. The calculations verified that the new impeller matches better with the original volute. Model-fan measured data was used to validate CFD predictions and impeller design goals. The CFD results further demonstrate a Reynolds-number effect between the model- and full-scale fans.

Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

Science.gov (United States)

Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.

2011-01-01

NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

Fan fiction, early Greece, and the historicity of canon

Directory of Open Access Journals (Sweden)

Ahuvia Kahane

2016-03-01

Full Text Available The historicity of canon is considered with an emphasis on contemporary fan fiction and early Greek oral epic traditions. The essay explores the idea of canon by highlighting historical variance, exposing wider conceptual isomorphisms, and formulating a revised notion of canonicity. Based on an analysis of canon in early Greece, the discussion moves away from the idea of canon as a set of valued works and toward canon as a practice of containment in response to inherent states of surplus. This view of canon is applied to the practice of fan fiction, reestablishing the idea of canonicity in fluid production environments within a revised, historically specific understanding in early oral traditions on the one hand and in digital cultures and fan fiction on the other. Several examples of early epigraphic Greek texts embedded in oral environments are analyzed and assessed in terms of their implications for an understanding of fan fiction and its modern contexts.

Vision for a worldwide fluvial-sediment information network

Science.gov (United States)

Gray, J.R.; Osterkamp, W.R.

2007-01-01

The nations of the world suffer both from the deleterious effects of some natural and human-altered fluxes of fluvial sediment and a lack of consistent and reliable information on the temporal and spatial occurrence of fluvial sediments. Decades ago, this difficulty was unavoidable due to a lack of understanding of the magnitude and scope of environmental influences exerted by fluvial sediment coupled with a dearth of tools for monitoring and studying the data. Such is no longer the case.

14 CFR 29.908 - Cooling fans.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling fans. 29.908 Section 29.908... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant General § 29.908 Cooling fans. For cooling fans that are a part of a powerplant installation the following apply: (a) Category A. For cooling fans installed...

Stranger than fiction: Fan identity in cosplay

Directory of Open Access Journals (Sweden)

Nicolle Lamerichs

2011-09-01

Full Text Available Academic accounts of fan cultures usually focus on creative practices such as fan fiction, fan videos, and fan art. Through these practices, fans, as an active audience, closely interpret existing texts and rework them with texts of their own. A practice scarcely examined is cosplay ("costume play", in which fans produce their own costumes inspired by fictional characters. Cosplay is a form of appropriation that transforms and actualizes an existing story in close connection to the fan community and the fan's own identity. I provide analytical insights into this fan practice, focusing on how it influences the subject. Cosplay is understood as a performative activity and analyzed through Judith Butler's concept of performativity. I specifically focus on boundaries between the body and dress, and on those between reality and fiction. I aim to show that cosplay emphasizes the personal enactment of a narrative, thereby offering new perspectives on fan identity.

yi fan zheng

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. YI FAN ZHENG. Articles written in Bulletin of Materials Science. Volume 40 Issue 7 December 2017 pp 1329-1333. Synthesis and enhanced photocatalytic activity of g-C 3 N 4 hybridized CdS nanoparticles · QING YING LIU YI LING QI YI FAN ZHENG XU CHUN SONG.

Design features of fans, blowers, and compressors

Science.gov (United States)

Cheremisinoff, N. P.; Cheremisinoff, P. N.

Fan engineering and compression machines are discussed. Basic aspects of fan performance and design are reviewed, and the design and performance characteristics of radial-flow fans, axial-flow fans, and controllable pitch fans are examined in detail. Air-conditioning systems are discussed, and noise, vibration, and mechanical considerations in fans are extensively examined. The thermodynamic principles governing compression machines are reviewed, and piston compressors, rotary compressors, blowers, and centrifugal compressors are discussed.

Analysis of impact resistance of composite fan blade. Fukugozai fan blade no taishogekisei no kaiseki

Energy Technology Data Exchange (ETDEWEB)

Miyachi, T; Okumura, H; Otake, K; Sofue, Y [Japan Society for Aeronautical and Space Sciences, Tokyo (Japan)

1992-01-05

Numerical analysis of impact response was carried out when a bird strike was simulated to study the applicability of fiber reinforced composite material to fan blades for turbo-fan engines. The validity of the numerical analysis was verified by comparing the analyzed results with impact tested results of a fan-blade model of Ti-alloy. The impact resistance was studied by applying this method to fan blades of composite materials such as carbon fiber, epoxy resin and carbon-silicate fiber reinforced Ti-alloy. The finite element method was used for the analysis by dividing the model into triangular flat elements. The relation between the impact load, the deformation of blade and the strain, the natural frequency characteristics, the elastic modulus and hetrogeneity of blade were considered to analyze the impact response. The impact load by the strike of 1.5 lbs bird is very severe to the fan blades for turbo-fan engines having the thrust of 5 ton class. 23 refs., 23 figs., 3 tabs.

Optimization of the Hockey Fans in Training (Hockey FIT) weight loss and healthy lifestyle program for male hockey fans.

Science.gov (United States)

Blunt, Wendy; Gill, Dawn P; Sibbald, Shannon L; Riggin, Brendan; Pulford, Roseanne W; Scott, Ryan; Danylchuk, Karen; Gray, Cindy M; Wyke, Sally; Bunn, Christopher; Petrella, Robert J

2017-11-28

The health outcomes of men continue to be poorer than women globally. Challenges in addressing this problem include difficulties engaging men in weight loss programs as they tend to view these programs as contrary to the masculine narrative of independence and self-reliance. Researchers have been turning towards sports fans to engage men in health promotion programs as sports fans are typically male, and tend to have poor health habits. Developed from the highly successful gender-sensitized Football Fans in Training program, Hockey Fans in Training (Hockey FIT) recruited 80 male hockey fans of the London Knights and Sarnia Sting who were overweight or obese into a weekly, 90-minute classroom education and group exercise program held over 12 weeks; a 40-week minimally-supported phase followed. A process evaluation of the Hockey FIT program was completed alongside a pragmatic randomized controlled trial and outcome evaluation in order to fully explore the acceptability of the Hockey FIT program from the perspectives of coaches delivering and participants engaged in the program. Data sources included attendance records, participant focus groups, coach interviews, assessment of fidelity (program observations and post-session coach reflections), and 12-month participant interviews. Coaches enjoyed delivering the program and found it simple to deliver. Men valued being among others of similar body shape and similar weight loss goals, and found the knowledge they gained through the program helped them to make and maintain health behaviour changes. Suggested improvements include having more hockey-related information and activities, greater flexibility with timing of program delivery, and greater promotion of technology support tools. We confirmed Hockey FIT was an acceptable "gender-sensitized" health promotion program for male hockey fans who were overweight or obese. Minor changes were required for optimization, which will be evaluated in a future definitive trial

ENERGY STAR Certified Ceiling Fans

Science.gov (United States)

Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=ceiling_fans.pr_crit_ceiling_fans

ENERGY STAR Certified Ventilating Fans

Science.gov (United States)

Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of October 1, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=vent_fans.pr_crit_vent_fans

An inventory and risk-based prioritization of Steep Creek Fans in Alberta, Canada

Directory of Open Access Journals (Sweden)

Holm Kris

2016-01-01

Full Text Available In June 2013, heavy rainfall caused flooding on most rivers in the province of Alberta, Canada, producing one of Canada’s most expensive natural disasters with about $6 billion (CDN in damage. Flooding inundated several municipalities including downtown Calgary, the fourth-largest city in Canada. Debris flows and debris floods caused extensive highway closures and damages to development on alluvial fans. Following these events, the Government of Alberta requested an inventory of all fans intersecting municipal development, major roads and highways in Alberta. Such fans may be subject to debris flow, debris flood (mud flows, and/or flood hazards. The study area spans the entirety of the Alberta Rocky Mountains, approximately 51,000 km2 (7% of Alberta. We characterize 710 fans in terms of hazard level and presence and types of elements at risk. We statistically analyse watershed attributes to predict the dominant fan hydrogeomorphic process types. All fans under provincial jurisdiction are assigned priority ratings based on hazard levels and the presence and value of elements at risk. The prioritization is risk-based as it considers both hazards and potential consequences. Of the fans prioritized, 13% intersected parcels containing land and residential developments with an assessed value of $2.4 billion (CDN, and the remainder were crossed by roads, pipelines or transmission lines. We present the study results on an interactive, searchable web application that can support ongoing hazard and risk assessments and risk reduction planning.

The Quaternary alluvial systems tract of the Pantanal Basin, Brazil

Directory of Open Access Journals (Sweden)

Mario Luis Assine

Full Text Available ABSTRACT The Pantanal Basin is an active sedimentary basin in central-west Brazil that consists of a complex alluvial systems tract characterized by the interaction between different river systems developed in one of the largest wetlands in the world. The Paraguay River is the trunk river system that drains the water and part of the sediment load received from areas outside of the basin. Depositional styles vary considerably along the river profiles throughout the basin, with the development of entrenched meandering belts, anastomosing reaches, and floodplain ponds. Paleodrainage patterns are preserved on the surface of abandoned lobes of fluvial fans, which also exhibit many degradational channels. Here, we propose a novel classification scheme according to which the geomorphology, hydrological regime and sedimentary dynamics of these fluvial systems are determined by the geology and geomorphology of the source areas. In this way, the following systems are recognized and described: (I the Paraguay trunk-river plains; (II fluvial fans sourced by the tablelands catchment area; (III fluvial fans sourced by lowlands; and (IV fluvial interfans. We highlight the importance of considering the influences of source areas when interpreting contrasting styles of fluvial architectures in the rock record.

Computing Gröbner fans

DEFF Research Database (Denmark)

Fukuda, K.; Jensen, Anders Nedergaard; Thomas, R.R.

2005-01-01

This paper presents algorithms for computing the Gröbner fan of an arbitrary polynomial ideal. The computation involves enumeration of all reduced Gröbner bases of the ideal. Our algorithms are based on a uniform definition of the Gröbner fan that applies to both homogeneous and non......-homogeneous ideals and a proof that this object is a polyhedral complex. We show that the cells of a Gröbner fan can easily be oriented acyclically and with a unique sink, allowing their enumeration by the memory-less reverse search procedure. The significance of this follows from the fact that Gröbner fans...... are not always normal fans of polyhedra in which case reverse search applies automatically. Computational results using our implementation of these algorithms in the software package Gfan are included....

Two-Stage Centrifugal Fan

Science.gov (United States)

Converse, David

2011-01-01

Fan designs are often constrained by envelope, rotational speed, weight, and power. Aerodynamic performance and motor electrical performance are heavily influenced by rotational speed. The fan used in this work is at a practical limit for rotational speed due to motor performance characteristics, and there is no more space available in the packaging for a larger fan. The pressure rise requirements keep growing. The way to ordinarily accommodate a higher DP is to spin faster or grow the fan rotor diameter. The invention is to put two radially oriented stages on a single disk. Flow enters the first stage from the center; energy is imparted to the flow in the first stage blades, the flow is redirected some amount opposite to the direction of rotation in the fixed stators, and more energy is imparted to the flow in the second- stage blades. Without increasing either rotational speed or disk diameter, it is believed that as much as 50 percent more DP can be achieved with this design than with an ordinary, single-stage centrifugal design. This invention is useful primarily for fans having relatively low flow rates with relatively high pressure rise requirements.

Electric fans for reducing adverse health impacts in heatwaves.

Science.gov (United States)

Gupta, Saurabh; Carmichael, Catriona; Simpson, Christina; Clarke, Mike J; Allen, Claire; Gao, Yang; Chan, Emily Y Y; Murray, Virginia

2012-07-11

Heatwaves are hot weather events, which breach regional or national thresholds, that last for several days. They are likely to occur with increasing frequency in some parts of the world. The potential consequences were illustrated in Europe in August 2003 when there were an estimated 30,000 excess deaths due to a heatwave. Electric fans might be used with the intention of reducing the adverse health effects of a heatwave. Fans do not cool the ambient air but can be used to draw in cooler air from outside when placed at an open window. The aim of the fans would be to increase heat loss by increasing the efficiency of all normal methods of heat loss, but particularly by evaporation and convection methods. However, it should be noted that increased sweating can lead to dehydration and electrolyte imbalances if these fluids and electrolytes are not replaced quickly enough. Research has also identified important gaps in knowledge about the use of fans, which might lead to their inappropriate use. To determine whether the use of electric fans contributes to, or impedes, heat loss at high ambient temperatures during a heatwave, and to contribute to the evidence base for the public health impacts of heatwaves. We sought unpublished and published studies that had been published in any language. The review team were able to assess studies reported in English, Chinese, Dutch, French and German; and reports in other languages would have been translated into English as necessary. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, the Indian biomedical literature (IndMED and MedIND) and databases of Chinese literature (Chinese Journal Net and Digital Periodical of WanFang Data). The most recent electronic searches were done in April 2012. We also checked the reference lists of relevant articles and the websites of relevant national and international organisations, and consulted with researchers and policy makers with experience in

Cost Effective, Ultra Sensitive Groundwater Monitoring for Site Remediation and Management

Science.gov (United States)

2015-05-01

evaporites, sandstone, gravel, conglomerate, and andesitic basalt . Closed basin; playa, alluvial fan, fluvial 600 to 10,000+ Unconfined, leaky...confined Lower unit Breccia, conglomerate, sandstone, siltstone, and local basaltic to rhyolitic flows and pyroclastic rocks. Alluvial fan, fluvial...with large volumes of groundwater. Three of the cartridges additionally protected by glass fiber filters (Acrodisc AP-4523; Pall GmbH, Dreieich, GE

PICNIC - FANS, ULTRAS AND HOOLIGANS - INTERNAL DIFFERENTIATE OF SUBCULTURE GROUP FOOTBALL FANS IN POLAND

Directory of Open Access Journals (Sweden)

Maciej Solinski

2006-01-01

Full Text Available This article is a main part of "Internal differentiate of subculture group of football fans in Poland" project. Author has tried to show how the subculture of football fans can be differentiate. Author ha presented three different subgroups of Polish fans. It is very important to divide this subculture, because each subgroup has different mentality and style. That is why I have paid the most attention on this element.

Laboratory alluvial fans in one dimension.

Science.gov (United States)

Guerit, L; Métivier, F; Devauchelle, O; Lajeunesse, E; Barrier, L

2014-08-01

When they reach a flat plain, rivers often deposit their sediment load into a cone-shaped structure called alluvial fan. We present a simplified experimental setup that reproduces, in one dimension, basic features of alluvial fans. A mixture of water and glycerol transports and deposits glass beads between two transparent panels separated by a narrow gap. As the beads, which mimic natural sediments, get deposited in this gap, they form an almost one-dimensional fan. At a moderate sediment discharge, the fan grows quasistatically and maintains its slope just above the threshold for sediment transport. The water discharge determines this critical slope. At leading order, the sediment discharge only controls the velocity at which the fan grows. A more detailed analysis reveals a slight curvature of the fan profile, which relates directly to the rate at which sediments are transported.

A fluvial mercury budget for Lake Ontario.

Science.gov (United States)

Denkenberger, Joseph S; Driscoll, Charles T; Mason, Edward; Branfireun, Brian; Warnock, Ashley

2014-06-03

Watershed mercury (Hg) flux was calculated for ten inflowing rivers and the outlet for Lake Ontario using empirical measurements from two independent field-sampling programs. Total Hg (THg) flux for nine study watersheds that directly drain into the lake ranged from 0.2 kg/yr to 13 kg/yr, with the dominant fluvial THg load from the Niagara River at 154 kg/yr. THg loss at the outlet (St. Lawrence River) was 68 kg/yr and has declined approximately 40% over the past decade. Fluvial Hg inputs largely (62%) occur in the dissolved fraction and are similar to estimates of atmospheric Hg inputs. Fluvial mass balances suggest strong in-lake retention of particulate Hg inputs (99%), compared to dissolved total Hg (45%) and methyl Hg (22%) fractions. Wetland land cover is a good predictor of methyl Hg yield for Lake Ontario watersheds. Sediment deposition studies, coupled atmospheric and fluvial Hg fluxes, and a comparison of this work with previous measurements indicate that Lake Ontario is a net sink of Hg inputs and not at steady state likely because of recent decreases in point source inputs and atmospheric Hg deposition.

Advanced Low-Noise Research Fan Stage Design

Science.gov (United States)

Neubert, Robert; Bock, Larry; Malmborg, Eric; Owen-Peer, William

1997-01-01

This report describes the design of the Advanced Low-Noise Research Fan stage. The fan is a variable pitch design, which is designed at the cruise pitch condition. Relative to the cruise setting, the blade is closed at takeoff and opened for reverse thrust operation. The fan stage is a split flow design with fan exit guide vanes (FEGVs) and core stators. The fan stage design is combined with a nacelle and engine core duct to form a powered fan/nacelle subscale model. This model is intended for use in combined aerodynamic, acoustic, and structural testing in a wind tunnel. The fan has an outer diameter of 22 in. and a hub-to-tip of 0.426 in., which allows the use of existing NASA fan and cowl force balance and rig drive systems. The design parameters were selected to permit valid acoustic and aerodynamic comparisons with the Pratt & Whitney (P&W) 17- and 22-in. rigs previously tested under NASA contract. The fan stage design is described in detail. The results of the design axisymmetric and Navier-Stokes aerodynamic analysis are presented at the critical design conditions. The structural analysis of the fan rotor and attachment is included. The blade and attachment are predicted to have adequate low-cycle fatigue life and an acceptable operating range without resonant stress or flutter. The stage was acoustically designed with airfoil counts in the FEGV and core stator to minimize noise. A fan/FEGV tone analysis developed separately under NASA contract was used to determine the optimum airfoil counts. The fan stage was matched to the existing nacelle, designed under the previous P&W low-noise contract, to form a fan/nacelle model for wind tunnel testing. It is an axisymmetric nacelle for convenience in testing and analysis. Previous testing confirmed that the nacelle performed as required at various aircraft operating conditions.

Fans af Bruce

DEFF Research Database (Denmark)

Vaaben, Nana Katrine

2007-01-01

Analysen viser, hvordan det samme ritual under en koncert forener og opdeler de fans, der orienterer sig mod Bruce Springsteen. På den ene side forener ritualet hele publikum i en stor fælles "Intimitet for mange" og på den anden side splitter det dem, fordi det bliver tydeligt, hvem der er de...... rigtige fans, og hvem der tilhører "pøbelen"....

Harmonic Balance Computations of Fan Aeroelastic Stability

Science.gov (United States)

Bakhle, Milind A.; Reddy, T. S. R.

2010-01-01

A harmonic balance (HB) aeroelastic analysis, which has been recently developed, was used to determine the aeroelastic stability (flutter) characteristics of an experimental fan. To assess the numerical accuracy of this HB aeroelastic analysis, a time-domain aeroelastic analysis was also used to determine the aeroelastic stability characteristics of the same fan. Both of these three-dimensional analysis codes model the unsteady flowfield due to blade vibrations using the Reynolds-averaged Navier-Stokes (RANS) equations. In the HB analysis, the unsteady flow equations are converted to a HB form and solved using a pseudo-time marching method. In the time-domain analysis, the unsteady flow equations are solved using an implicit time-marching approach. Steady and unsteady computations for two vibration modes were carried out at two rotational speeds: 100 percent (design) and 70 percent (part-speed). The steady and unsteady results obtained from the two analysis methods compare well, thus verifying the recently developed HB aeroelastic analysis. Based on the results, the experimental fan was found to have no aeroelastic instability (flutter) at the conditions examined in this study.

A combined morphometric, sedimentary, GIS and modelling analysis of flooding and debris flow hazard on a composite alluvial fan, Caveside, Tasmania

Science.gov (United States)

Kain, Claire L.; Rigby, Edward H.; Mazengarb, Colin

2018-02-01

Two episodes of intense flooding and sediment movement occurred in the Westmorland Stream alluvial system near Caveside, Australia in January 2011 and June 2016. The events were investigated in order to better understand the drivers and functioning of this composite alluvial system on a larger scale, so as to provide awareness of the potential hazard from future flood and debris flow events. A novel combination of methods was employed, including field surveys, catchment morphometry, GIS mapping from LiDAR and aerial imagery, and hydraulic modelling using RiverFlow-2D software. Both events were initiated by extreme rainfall events (events on the farmland appeared similar; however, there were differences in sediment source and transport processes that have implications for understanding recurrence probabilities. A debris flow was a key driver in the 2011 event, by eroding the stream channel in the forested watershed and delivering a large volume of sediment downstream to the alluvial fan. In contrast, modelled flooding velocities suggest the impacts of the 2016 event were the result of an extended period of extreme stream flooding and consequent erosion of alluvium directly above the current fan apex. The morphometry of the catchment is better aligned with values from fluvially dominated fans found elsewhere, which suggests that flooding represents a more frequent future risk than debris flows. These findings have wider implications for the estimation of debris flow and flood hazard on alluvial fans in Tasmania and elsewhere, as well as further demonstrating the capacity of combined hydraulic modelling and geomorphologic investigation as a predictive tool to inform hazard management practices in environments affected by flooding and sediment movement.

Experimental Evaluation of Installed Cooking Exhaust Fan Performance

Energy Technology Data Exchange (ETDEWEB)

Singer, Brett C.; Delp, William W.; Apte, Michael G.

2010-11-01

The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range (MOR) units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one wall-mount chimney), four under-cabinet open hoods, and two open hoods with chimney mounts over islands. Performance assessment included measurement of airflow and sound levels across fan settings and experiments to quantify the contemporaneous capture efficiency for the exhaust generated by natural gas cooking burners.Capture efficiency is defined as the fraction of generated pollutants that are removed through the exhaust and thus not available for inhalation of household occupants. Capture efficiency (CE) was assessed for various configurations of burner use (e.g., single front, single back, combination of one front and one back, oven) and fan speed setting. Measured airflow rates were substantially lower than the levels noted in product literature for many of the units. This shortfall was observed for several units costing in excess of $1000. Capture efficiency varied widely (from<5percent to roughly 100percent) across devices and across conditions for some devices. As expected, higher capture efficiencies were achieved with higher fan settings and the associated higher air flow rates. In most cases, capture efficiencies were substantially higher for rear burners than for front burners. The best and most consistent performance was observed for open hoods that covered all cooktop burners and operated at higher airflow rates. The lowest capture efficiencies were measured when a front burner was used with a rear backdraft system or with lowest fan setting for above the range

The origin of dose distributions in fluvial sediments, and the prospect of dating single grains from fluvial deposits using optically stimulated luminescence

International Nuclear Information System (INIS)

Olley, J.M.; Caitcheon, G.G.; Roberts, R.G.

1999-01-01

We examine the causes of the asymmetric distributions of dose observed from measurements of the optically stimulated luminescence emitted by small aliquots of fluvial quartz, and deduce that the asymmetry arises as a result of samples being composed of a mix of mainly well bleached grains with grains that were effectively unbleached at the time of deposition. We demonstrate that the shapes of the dose distributions can be used to assess the likelihood that aliquots consist only of grains that were well-bleached at the time of deposition. The more asymmetric the distribution, the greater the probability that the aliquots with the lowest dose most closely represent the true burial dose. Single grains with differing doses are present in each of the samples examined, and the population with the lowest dose gives an optical age consistent with the expected burial age. This result implies that the beta-dose heterogeneity in these deposits is small, and that the effects of micro-dosimetric variations on optical dating of individual grains are not significant for these samples. We demonstrate that single-grain dating of fluvial material is possible and practicable using standard Risoe optical dating equipment, and we conclude that application of a new regenerative-dose protocol to single grains of quartz, using the lowest dose population to estimate the burial dose, is the best available means of obtaining reliable luminescence ages for heterogeneously bleached fluvial sediments

Experiencing fan activism: Understanding the power of fan activist organizations through members' narratives

Directory of Open Access Journals (Sweden)

Neta Kligler-Vilenchik

2012-06-01

Full Text Available Fan activism, forms of civic engagement and political participation growing out of experiences of fandom, is a powerful mode of mobilization, particularly for young people. Building on 40 interviews with members of two organizations representing different configurations of fan activism, this article discusses three emerging elements that are key to the experience of membership in such groups. We suggest that the strength of fan activist groups builds on successfully combining these elements: two that are common to fandom, shared media experiences and a sense of community, and one that is traditionally ascribed to volunteerism and activism, the wish to help.

CFD Study of an Annular-Ducted Fan Lift System for VTOL Aircraft

Directory of Open Access Journals (Sweden)

Yun Jiang

2015-09-01

Full Text Available The present study aimed at assessing a novel annular-ducted fan lift system for VTOL aircraft through computational fluid dynamics (CFD simulations. The power and lift efficiency of the lift fan system in hover mode, the lift and drag in transition mode, the drag and flight speed of the aircraft in cruise mode and the pneumatic coupling of the tip turbine and jet exhaust were studied. The results show that the annular-ducted fan lift system can have higher lift efficiency compared to the rotor of the Apache helicopter; the smooth transition from vertical takeoff to cruise flight needs some extra forward thrust to overcome a low peak of drag; the aircraft with the lift fan system enclosed during cruise flight theoretically may fly faster than helicopters and tiltrotors based on aerodynamic drag prediction, due to the elimination of rotor drag and compressibility effects on the rotor blade tips; and pneumatic coupling of the tip turbine and jet exhaust of a 300 m/s velocity can provide enough moment to spin the lift fan. The CFD results provide insight for future experimental study of the annular-ducted lift fan VTOL aircraft.

The creation of football slash fan fiction

Directory of Open Access Journals (Sweden)

Abby Waysdorf

2015-06-01

Full Text Available Although sports fandom and fan fiction are often thought of as different worlds, in the contemporary media environment, this is not the case. Sport is a popular source text for fan fiction, and high-level European football, one of the world's most watched sports, has long had an online fan fiction presence. In a study of the LiveJournal community Footballslash over the 2011–12 European football season, I investigate what makes football a suitable source text for fan fiction, especially slash fan fiction; what fan fiction authors are doing with football; and what this suggests about how football and fan fiction are used in the present day. I present a new understanding of football as a media text to be transformed as well as provide an in-depth look into how this type of real person slash is developed and thought of by its practitioners. In doing so, I show what happens when fandoms and fan practices converge in the 21st century.

The Brahmaputra River: a stratigraphic analysis of Holocene avulsion and fluvial valley reoccupation history

Science.gov (United States)

Hartzog, T. R.; Goodbred, S. L.

2011-12-01

The Brahmaputra River, one of the world's largest braided streams, is a major component of commerce, agriculture, and transportation in India and Bangladesh. Hence any significant change in course, morphology, or behavior would be likely to influence the regional culture and economy that relies on this major river system. The history of such changes is recorded in the stratigraphy deposited by the Brahmaputra River during the Holocene. Here we present stratigraphic analysis of sediment samples from the boring of 41 tube wells over a 120 km transect in the upper Bengal Basin of northern Bangladesh. The transect crosses both the modern fluvial valley and an abandoned fluvial valley about 60 km downstream of a major avulsion node. Although the modern Brahmaputra does not transport gravel, gravel strata are common below 20 m with fluvial sand deposits dominating most of the stratigraphy. Furthermore, the stratigraphy preserves very few floodplain mud strata below the modern floodplain mud cap. These preliminary findings will be assessed to determine their importance in defining past channel migration, avulsion frequency, and the reoccupation of abandoned fluvial valleys. Understanding the avulsion and valley reoccupation history of the Brahmaputra River is important to assess the risk involved with developing agriculture, business, and infrastructure on the banks of modern and abandoned channels. Based on the correlation of stratigraphy and digital surface elevation data, we hypothesize that the towns of Jamalpur and Sherpur in northern Bangladesh were once major ports on the Brahmaputra River even though they now lie on the banks of small underfit stream channels. If Jamalpur and Sherpur represent the outer extent of the Brahmaputra River braid-belt before the last major avulsion, these cities and any communities developed in the abandoned braid-belt assume a high risk of devastation if the next major avulsion reoccupies this fluvial valley. It is important to

30 CFR 75.302 - Main mine fans.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fans. 75.302 Section 75.302 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.302 Main mine fans. Each coal mine shall be ventilated by one or more main mine fans. Booster fans shall not be installed underground to assist main mine...

Enhanced Fan Noise Modeling for Turbofan Engines

Science.gov (United States)

Krejsa, Eugene A.; Stone, James R.

2014-01-01

This report describes work by consultants to Diversitech Inc. for the NASA Glenn Research Center (GRC) to revise the fan noise prediction procedure based on fan noise data obtained in the 9- by 15 Foot Low-Speed Wind Tunnel at GRC. The purpose of this task is to begin development of an enhanced, analytical, more physics-based, fan noise prediction method applicable to commercial turbofan propulsion systems. The method is to be suitable for programming into a computational model for eventual incorporation into NASA's current aircraft system noise prediction computer codes. The scope of this task is in alignment with the mission of the Propulsion 21 research effort conducted by the coalition of NASA, state government, industry, and academia to develop aeropropulsion technologies. A model for fan noise prediction was developed based on measured noise levels for the R4 rotor with several outlet guide vane variations and three fan exhaust areas. The model predicts the complete fan noise spectrum, including broadband noise, tones, and for supersonic tip speeds, combination tones. Both spectra and directivity are predicted. Good agreement with data was achieved for all fan geometries. Comparisons with data from a second fan, the ADP fan, also showed good agreement.

30 CFR 57.8518 - Main and booster fans.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main and booster fans. 57.8518 Section 57.8518... and Underground § 57.8518 Main and booster fans. (a) All mine main and booster fans installed and used...-cycle shutdowns or planned or scheduled fan maintenance or fan adjustments where air quality is...

Beaver ponds' impact on fluvial processes (Beskid Niski Mts., SE Poland).

Science.gov (United States)

Giriat, Dorota; Gorczyca, Elżbieta; Sobucki, Mateusz

2016-02-15

Beaver (Castor sp.) can change the riverine environment through dam-building and other activities. The European beaver (Castor fiber) was extirpated in Poland by the nineteenth century, but populations are again present as a result of reintroductions that began in 1974. The goal of this paper is to assess the impact of beaver activity on montane fluvial system development by identifying and analysing changes in channel and valley morphology following expansion of beaver into a 7.5 km-long headwater reach of the upper Wisłoka River in southeast Poland. We document the distribution of beaver in the reach, the change in river profile, sedimentation type and storage in beaver ponds, and assess how beaver dams and ponds have altered channel and valley bottom morphology. The upper Wisłoka River fluvial system underwent a series of anthropogenic disturbances during the last few centuries. The rapid spread of C. fiber in the upper Wisłoka River valley was promoted by the valley's morphology, including a low-gradient channel and silty-sand deposits in the valley bottom. At the time of our survey (2011), beaver ponds occupied 17% of the length of the study reach channel. Two types of beaver dams were noted: in-channel dams and valley-wide dams. The primary effect of dams, investigated in an intensively studied 300-m long subreach (Radocyna Pond), was a change in the longitudinal profile from smooth to stepped, a local reduction of the water surface slope, and an increase in the variability of both the thalweg profile and surface water depths. We estimate the current rate of sedimentation in beaver ponds to be about 14 cm per year. A three-stage scheme of fluvial processes in the longitudinal and transverse profile of the river channel is proposed. C. fiber reintroduction may be considered as another important stage of the upper Wisłoka fluvial system development. Copyright © 2015 Elsevier B.V. All rights reserved.

Radon reduction using sub floor fans

International Nuclear Information System (INIS)

Harley, N.H.; Chittaporn, P.

1996-01-01

The basement and second floor 222 Rn concentrations in an energy efficient home were measured hourly for 6 y using continuous monitors of our design. The home had a subslab pipe network installed during construction, and for the past 2 y a 150 cfm fan was operative venting air via ductwork inside the chimney exiting on the roof. During this measurement interval, experiments were conducted with the fan in 3 modes: (1) with the subslab fan off, (2) in the conventional direction auctioning air from beneath the slab to outside, and (3) reversed, blowing outdoor air into the network under the slab. We have a large data base to show that the indoor 222 R n concentration varies inversely with the indoor/outdoor temperature difference. In order to compare the 3 fan modes directly, we selected 50 to 90 d periods when the outdoor temperature was essentially the same. For the 3 modes, the fan off, blowing upward, and blowing downward, the basement concentration averaged 80, 38, and 34 Bq m -3 , respectively. Radon peaks or surges occur over a period of about 1 d during falling barometric pressure. With the fan blowing downward, these 222 Rn peaks tend to be smaller but only marginally so. We conclude that in this home the reduction in 222 Rn with the fan and subslab pipe network operating was essentially the same regardless of the direction of flow from the fan

Assessing Potential Algal Blooms in a Shallow Fluvial Lake by Combining Hydrodynamic Modelling and Remote-Sensed Images

Directory of Open Access Journals (Sweden)

Monica Pinardi

2015-04-01

Full Text Available Shallow fluvial lakes are dynamic ecosystems shaped by physical and biological factors and characterized by the coexistence of phytoplankton and macrophytes. Due to multiple interplaying factors, understanding the distribution of phytoplankton in fluvial lakes is a complex but fundamental issue, in the context of increasing eutrophication, climate change, and multiple water uses. We analyze the distribution of phytoplankton by combining remotely sensed maps of chlorophyll-a with a hydrodynamic model in a dammed fluvial lake (Mantua Superior Lake, Northern Italy. The numerical simulation of different conditions shows that the main hydrodynamic effects which influence algal distribution are related to the combined effect of advection due to wind forces and local currents, as well as to the presence of large gyres which induce recirculation and stagnation regions, favoring phytoplankton accumulation. Therefore, the general characters of the phytoplankton horizontal patchiness can be inferred from the results of the hydrodynamic model. Conversely, hyperspectral remote-sensing products can be used to validate this model, as they provide chlorophyll-a distribution maps. The integration of ecological, hydraulic, and remote-sensing techniques may therefore help the monitoring and protection of inland water quality, with important improvements in management actions by policy makers.

Novel Crosstalk Measurement Method for Multi-Core Fiber Fan-In/Fan-Out Devices

DEFF Research Database (Denmark)

Ye, Feihong; Ono, Hirotaka; Abe, Yoshiteru

2016-01-01

We propose a new crosstalk measurement method for multi-core fiber fan-in/fan-out devices utilizing the Fresnel reflection. Compared with the traditional method using core-to-core coupling between a multi-core fiber and a single-mode fiber, the proposed method has the advantages of high reliability...

Dynamic response of Hovercraft lift fans

Science.gov (United States)

Moran, D. D.

1981-08-01

Hovercraft lift fans are subjected to varying back pressure due to wave action and craft motions when these vehicles are operating in a seaway. The oscillatory back pressure causes the fans to perform dynamically, exhibiting a hysteresis type of response and a corresponding degradation in mean performance. Since Hovercraft motions are influenced by variations in lift fan pressure and discharge, it is important to understand completely the nature of the dynamic performance of lift fans in order to completely solve the Hovercraft seakeeping problem. The present study was performed to determine and classify the instabilities encountered in a centrifugal fan operating against time-varying back pressure. A model-scale experiment was developed in which the fan discharge was directed into a flow-measuring device, terminating in a rotating valve which produced an oscillatory back pressure superimposed upon a mean aerodynamic resistance. Pressure and local velocity were measured as functions of time at several locations in the fan volute. The measurements permitted the identification of rotating (or propagating) stall in the impeller. One cell and two cell configurations were classified and the transient condition connecting these two configurations was observed. The mechanisms which lead to rotating stall in a centrifugal compressor are presented and discussed with specific reference to Hovercraft applications.

Acceptance test report MICON software exhaust fan control

International Nuclear Information System (INIS)

Keck, R.D.

1998-01-01

This test procedure specifies instructions for acceptance testing of software for exhaust fan control under Project ESPT (Energy Savings Performance Contract). The software controls the operation of two emergency exhaust fans when there is a power failure. This report details the results of acceptance testing for the MICON software upgrades. One of the modifications is that only one of the emergency fans will operate at all times. If the operating fan shuts off or fails, the other fan will start and the operating fan will be stopped

Extreme Changes in Stream Geomorphic Conditions induced by Fluvial Scour in Bridges

Science.gov (United States)

Özcan, O.; Ozcan, O.

2016-12-01

The numerous complexities associated with bridge scour have caused scour to be one of the most active topics of stream geomorphic research. The assessment of local scouring mechanism around bridge piers provides information for decision-making regarding the pile footing design, predicting the safety of bridges under critical scoured conditions, and as a result, may help prevent unnecessary loses. In the study, bridge design plans and HEC-RAS modeling were used for the assessment of changes in stream geomorphic conditions. The derived fluvial scour depths were compared with the field measurements and the empirical formula which is based on stream flow discharge rate, streambed condition and shape of river. Preliminary results revealed that bridge damage resulting from the flood event in 2003 induced substantial scour around bridge piles. Afterwards, significant stream bed change was observed under the influence of fluvial scour in another flood occurred in 2009. Consequently, geomorphic conditions of the stream bed should be considered in the structural design of the bridges.

Introduction of a Cooling-Fan Efficiency Index

DEFF Research Database (Denmark)

Schiavon, S.; Melikov, Arsen Krikor

2009-01-01

In a warm environment, air movement with elevated velocity is a well-known cooling strategy. The local air movement is typically generated by cooling fans (e.g., ceiling fan, table fans, etc.). Appearance, power input, and price are the main parameters considered today when purchasing cooling fans...... in practice the recommended elevated velocities in warm environments presented in the present standards. The standards need to be revised....

Tune-Up Your Fan Systems for Improved Performance

Energy Technology Data Exchange (ETDEWEB)

2018-04-03

Fans are used extensively in commercial buildings and represent approximately 6% of total energy consumed by commercial buildings. The U.S. Department of Energy (DOE) estimates that fans in commercial buildings consume 158 billion kWh of electricity annually. Maintaining fan systems in proper condition provides energy savings and ensures a comfortable and healthy environment. While many fan systems have significant energy savings opportunities available through improvements in fan selection, system design, and operational practices, it is not always apparent when a fan system needs maintenance or what opportunities are available for improvements. This resource is designed for facility managers and maintenance staff to provide easy-to-implement actionable guidance on fan efficiency measures for existing ducted air systems.

Depositional conditions on an alluvial fan at the turn of the Weichselian to the Holocene – a case study in the Żmigród Basin, southwest Poland

Directory of Open Access Journals (Sweden)

Zieliński Paweł

2016-06-01

Full Text Available Presented are the results of research into the fluvio-aeolian sedimentary succession at the site of Postolin in the Żmigród Basin, southwest Poland. Based on lithofacies analysis, textural analysis, Thermoluminescence and Infrared-Optical Stimulated Luminescence dating and GIS analysis, three lithofacies units were recognised and their stratigraphic succession identified: 1 the lower unit was deposited during the Pleni-Weichselian within a sand-bed braided river functioning under permafrost conditions within the central part of the alluvial fan; 2 the middle unit is the result of aeolian deposition and fluvial redeposition on the surface of the fan during long-term permafrost and progressive decrease of humidity of the climate at the turn of the Pleni- to the Late Weichselian; 3 the upper unit accumulated following the development of longitudinal dunes at the turn of the Late Weichselian to the Holocene; the development of dunes was interrupted twice by the form being stabilised by vegetation and soil development.

Model Projections of Future Fluvial Sediment Delivery to Major Deltas Under Environmental Change

Science.gov (United States)

Darby, S. E.; Dunn, F.; Nicholls, R. J.; Cohen, S.; Zarfl, C.

2017-12-01

Deltas are important hot spots for climate change impacts on which over half a billion people live worldwide. Most of the world's deltas are sinking as a result of natural and anthropogenic subsidence and due to eustatic sea level rise. The ability to predict rates of delta aggradation is therefore critical to assessments of the extent to which sedimentation can potentially offset sea level rise, but our ability to make such predictions is severely hindered by a lack of insight into future trends of the fluvial sediment load supplied to their deltas by feeder watersheds. To address this gap we investigate fluvial sediment fluxes under future environmental change for a selection (47) of the world's major river deltas. Specifically, we employed the numerical model WBMsed to project future variations in mean annual fluvial sediment loads under a range of environmental change scenarios that account for changes in climate, socio-economics and dam construction. Our projections indicate a clear decrease (by 34 to 41% on average, depending on the specific scenario) in future fluvial sediment supply to most of the 47 deltas. These reductions in sediment delivery are driven primarily by anthropogenic disturbances, with reservoir construction being the most influential factor globally. Our results indicate the importance of developing new management strategies for reservoir construction and operation.

Investigating for failure of central ventilation fan blade

International Nuclear Information System (INIS)

Koo, Jae Raeyang; Ko Woo Sig; Kim, Yeon Hwan; Park, Kwang Ha

2002-01-01

During the operation, central ventilation fan stopped when switch 'on' condition. When central ventilation fan disassemble, ten blades of fan fractured. We have searched cause of failure. We had modeling one of the fan blades and analysis with computer programs. Thus we have find that fracture of central ventilation fan blades is alternative stress and vibration at hub. In this paper, we have described cause of failure

PFP supply fan motor starters

International Nuclear Information System (INIS)

Keck, R.D.

1995-01-01

The Plutonium Finishing Plant (PFP) is currently stabilizing about 25 kg of Pu sludge; upon completion of this task, PFP will be maintained in a safe standby condition to await decision from the PFP NEPA review. It can take about 10 years to initiate and complete terminal cleanout after this; the facility will then be decommissioned and decontaminated. The 234-5Z ventilation system must continue to operate until terminal cleanout. Part of the ventilation system is the seismic fan shutdown system which shuts down the ventilation supply fans in case of strong earthquake. This document presents criteria for installing solid state, reduced voltage motor starters and isolation contactors for the 8 main ventilation supply fans. The isolation contactors will shutdown the supply fans in event of earthquake

Megafans-Some New Perspectives from a Global Study

Science.gov (United States)

Wilkinson, M. Justin

2016-01-01

A global study of megafans (greater than 100 km long) has revealed their widespread existence on all continents, with almost 200 documented, 93 in Africa where research is most thorough. The largest measures 705 km. Megafans are a major subset of "DFS" (distributive fluvial systems, a category that includes all fan-like features greater than 30 km long). 1. Many researchers now recognize megafans as different from floodplains, small coarse-grained alluvial fans, and deltas. Although smaller architectural elements in megafans are the same as those encountered in floodplains (channel, overbank, etc.), larger architectures differ because of the unconfined setting of megafans, versus the valley-confined setting of floodplains. 2. A length continuum is now documented between steep alluvial fans 10-20 km in length, and fluvial fans 30-50 km long. This implies a continuum of process from end-member alluvial fan processes (e.g. high-energy flows that emplace gravels, debris-flow units) to the relatively fine-grained channel and overbank deposits common to purely fluvial fans. Combinations of these different processes will then occur in many mid-sized fans. 3. The global distribution suggests a prima facie relationship with tectonic environment rather than climatic zones, with local controls being the slope of the formative river and the existence of a basin subsiding below the long profile of the river. But the global population has revealed that most megafans are relict. So it is possible that further research will show relationships to prior climatic regimes. 4. Megafans can have regional importance: e.g., along the east flank of the central Andes, nested megafans total approximately 750,000 km2-and 1.2m km2 if all megafans in S. America are counted. Modern megafan landscapes thus have basinal importance, orders of magnitude greater than alluvial fan bajadas. 5. Because so many aggrading basins are dominated today by DFS, it is claimed that DFS ought to be significant in

Gold-bearing fluvial and associated tidal marine sediments of Proterozoic age in the Mporokoso Basin, northern Zambia

Science.gov (United States)

Andrews-Speed, C. P.

1986-07-01

The structurally defined Mporokoso Basin contains up to 5000 m of continental and marine clastic sediments and minor silicic volcanics which together form the Mporokoso Group. These rocks overlie unconformably a basement of silicic-intermediate igneous rocks and accumulated within the interval 1830-1130 Ma. This sedimentological study was restricted to the eastern end of the basin and was part of an assessment of the potential for palaeoplacer gold in the Mporokoso Group. At the base of the Mporokoso Group, the Mbala Formation consists of 1000-1500 m of purple sandstones and conglomerates deposited in a braided-stream system overlain by 500-1000 m of mature quartz arenites deposited in a tidal marine setting. A general coarsening-upward trend exists within the fluvial sediments. Sandy, distal braided-stream facies passes upwards into more proximal conglomeratic facies. In proximal sections, poorly sorted conglomerates form the top of the coarsening-up sequence which is 500-700 m thick. The overlying fluvial sediments fine upwards. The tidal marine sandstones at the top of the Mbala Formation resulted from reworking of fluvial sediments during a marine transgression. Well-exposed sections with fluvial conglomerates were studied in detail. Individual conglomerate bodies form sheets extending for hundreds of metres downstream and at least one hundred metres across stream, with little sign of deep scouring or channelling. They are generally matrix-supported. The whole fluvial sequence is characterised by a paucity of mud or silt. These conglomerates were deposited by large velocity, sheet flows of water which transported a bed-load of pebbles and sand. Most fine material settling out from suspension was eroded by the next flow. The great lateral and vertical extent and the uniformity of the fluvial sediments suggest that the sediments accumulated over an unconfined alluvial plain and that the tectonic evolution of the source area was relatively continuous and not

Acoustic Power Transmission Through a Ducted Fan

Science.gov (United States)

Envia, Ed

2016-01-01

For high-speed ducted fans, when the rotor flowfield is shock-free, the main contribution to the inlet radiated acoustic power comes from the portion of the rotor stator interaction sound field that is transmitted upstream through the rotor. As such, inclusion of the acoustic transmission is an essential ingredient in the prediction of the fan inlet noise when the fan tip relative speed is subsonic. This paper describes a linearized Euler based approach to computing the acoustic transmission of fan tones through the rotor. The approach is embodied in a code called LINFLUX was applied to a candidate subsonic fan called the Advanced Ducted Propulsor (ADP). The results from this study suggest that it is possible to make such prediction with sufficient fidelity to provide an indication of the acoustic transmission trends with the fan tip speed.

Field migration rates of tidal meanders recapitulate fluvial morphodynamics

Science.gov (United States)

Finotello, Alvise; Lanzoni, Stefano; Ghinassi, Massimiliano; Marani, Marco; Rinaldo, Andrea; D'Alpaos, Andrea

2018-02-01

The majority of tidal channels display marked meandering features. Despite their importance in oil-reservoir formation and tidal landscape morphology, questions remain on whether tidal-meander dynamics could be understood in terms of fluvial processes and theory. Key differences suggest otherwise, like the periodic reversal of landscape-forming tidal flows and the widely accepted empirical notion that tidal meanders are stable landscape features, in stark contrast with their migrating fluvial counterparts. On the contrary, here we show that, once properly normalized, observed migration rates of tidal and fluvial meanders are remarkably similar. Key to normalization is the role of tidal channel width that responds to the strong spatial gradients of landscape-forming flow rates and tidal prisms. We find that migration dynamics of tidal meanders agree with nonlinear theories for river meander evolution. Our results challenge the conventional view of tidal channels as stable landscape features and suggest that meandering tidal channels recapitulate many fluvial counterparts owing to large gradients of tidal prisms across meander wavelengths.

Active Control of Fan Noise: Feasibility Study. Volume 3; Active Fan Noise Cancellation in the NASA Lewis Active Noise Control Fan Facility

Science.gov (United States)

Pla, Frederic G.; Hu, Ziqiang; Sutliff, Daniel L.

1996-01-01

This report describes the Active Noise Cancellation (ANC) System designed by General Electric and tested in the NASA Lewis Research Center's (LERC) 48 inch Active Noise Control Fan (ANCF). The goal of this study is to assess the feasibility of using wall mounted secondary acoustic sources and sensors within the duct of a high bypass turbofan aircraft engine for global active noise cancellation of fan tones. The GE ANC system is based on a modal control approach. A known acoustic mode propagating in the fan duct is canceled using an array of flush-mounted compact sound sources. The canceling modal signal is generated by a modal controller. Inputs to the controller are signals from a shaft encoder and from a microphone array which senses the residual acoustic mode in the duct. The key results are that the (6,0) was completely eliminated at the 920 Hz design frequency and substantially reduced elsewhere. The total tone power was reduced 6.8 dB (out of a possible 9.8 dB). Farfield reductions of 15 dB (SPL) were obtained. The (4,0) and (4,1) modes were reduced simultaneously yielding a 15 dB PWL decrease. The results indicate that global attenuation of PWL at the target frequency was obtained in the aft quadrant using an ANC actuator and sensor system totally contained within the duct. The quality of the results depended on precise mode generation. High spillover into spurious modes generated by the ANC actuator array caused less than optimum levels of PWL reduction. The variation in spillover is believed to be due to calibration procedure, but must be confirmed in subsequent tests.

On the study of wavy leading-edge vanes to achieve low fan interaction noise

Science.gov (United States)

Tong, Fan; Qiao, Weiyang; Xu, Kunbo; Wang, Liangfeng; Chen, Weijie; Wang, Xunnian

2018-04-01

The application of wavy leading-edge vanes to reduce a single-stage axial fan noise is numerically studied. The aerodynamic and acoustic performance of the fan is numerically investigated using a hybrid unsteady Reynolds averaged Navier-Stokes (URANS)/acoustic analogy method (Goldstein equations). First, the hybrid URANS/Goldstein method is developed and successfully validated against experiment results. Next, numerical simulations are performed to investigate the noise reduction effects of the wavy leading-edge vanes. The aerodynamic and acoustic performance is assessed for a fan with vanes equipped with two different wavy leading-edge profiles and compared with the performance of conventional straight leading-edge vanes. Results indicate that a fan with wavy leading-edge vanes produces lower interaction noise than the baseline fan without a significant loss in aerodynamic performance. In fact, it is demonstrated that wavy leading-edge vanes have the potential to lead to both aerodynamic and acoustic improvements. The two different wavy leading-edge profiles are shown to successfully reduce the fan tone sound power level by 1.2 dB and 4.3 dB, respectively. Fan efficiency is also improved by about 1% with one of the tested wavy leading-edge profiles. Large eddy simulation (LES) is also performed for a simplified fan stage model to assess the effects of wavy leading-edge vanes on the broadband fan noise. Results indicate that the overall sound power level of a fan can be reduced by about 4 dB with the larger wavy leading-edge profile. Finally, the noise reduction mechanisms are investigated and analysed. It is found that the wavy leading-edge profiles can induce significant streamwise vorticity around the leading-edge protuberances and reduce pressure fluctuations (especially at locations of wavy leading-edge hills) and unsteady forces on the stator vanes. The underlying mechanism of the reduced pressure fluctuations is also discussed by examining the magnitude

Alternative marine and fluvial models for the non-fossiliferous quartzitic sandstones of the Early Proterozoic Daspoort Formation, Transvaal Sequence of southern Africa

Science.gov (United States)

Eriksson, P. G.; Schreiber, U. M.; van der Neut, M.; Labuschagne, H.; Van Der Schyff, W.; Potgieter, G.

1993-04-01

This paper discusses some of the problems related to the palaeoenvironmental interpretation of non-fossiliferous, early Precambrian, recrystallised quartzitic sandstones, using the Early Proterozoic Daspoort Formation, Transvaal Sequence of southern Africa as a case study. These cross-bedded and planar stratified rocks have been interpreted previously as shallow marine deposits, based on limited studies of areas with well-exposed, relatively undeformed outcrops. This postulate rests largely on the apparently mature nature of the recrystallised sandstones and their thin bedding. Examination of outcrops throughout the preserved basin, including those which have been deformed and metamorphosed, reveals the presence of subordinate immature sandstones. Lateral facies relationships permit an alternative distal fan-fluvial braidplain model to be proposed. This is compatible with collected palaeocurrent data, thicknes trends and results of thin section petrography.

Improving the energy efficiency of mine fan assemblages

International Nuclear Information System (INIS)

De Souza, Euler

2015-01-01

Energy associated with ventilating an underground operation comprises a significant portion of a mine operation's base energy demand and is consequently responsible for a large percentage of the total operating costs. Ventilation systems may account from 25 to 40% of the total energy costs and 40–50% of the energy consumption of a mine operation. Fans are the most important mechanical devices used to ventilate underground mines and the total fan power installed in a single mine operation can easily exceed 10,000 kW. Investigations of a number of mine main fan installations have determined their assemblage to be, in general, very energy inefficient. The author has found that 40–80% of the energy consumed by a main fan is used to overcome the resistance of fan assemblage components. This paper presents how engineering design principles can be applied to improve the performance and efficiency of fan installations, resulting in substantial reductions in power consumption, operating cost and greenhouse gas emissions. A detailed case study is presented to demonstrate that, by designing fan assemblages using proper engineering concepts of fluid physics and industrial ventilation design, main fan systems will operate at efficiencies well above 80–90% (compared to common operating efficiencies of between 20 and 65%), resulting in a drastic reduction in a mine's overall costs and base electrical and energy loads. - Highlights: • Increases in fan assemblage efficiencies with minimum capital investment. • Improved designs for substantial fan power and operating cost savings. • General solutions and tactics for improving existing main fan installations. • Case study presented to demonstrate proper design of fan assemblages.

30 CFR 75.331 - Auxiliary fans and tubing.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans and tubing. 75.331 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.331 Auxiliary fans and tubing. (a) When auxiliary fans and tubing are used for face ventilation, each auxiliary fan shall be— (1...

30 CFR 57.8519 - Underground main fan controls.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground main fan controls. 57.8519 Section... Ventilation Surface and Underground § 57.8519 Underground main fan controls. All underground main fans shall have controls placed at a suitable protected location remote from the fan and preferably on the surface...

The contribution of bank and surface sediments to fluvial sediment ...

African Journals Online (AJOL)

The contribution of bank and surface sediments to fluvial sediment transport of the Pra River. ... the relative contribution of surface and bank sediments to the fluvial sediment transport. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Ferromanganese micronodules from Bengal Fan

Digital Repository Service at National Institute of Oceanography (India)

Chauhan, O.S.; Gujar, A.R.; Rao, Ch.M.

The occurrence of ferromanganese micronodules, hitherto unreported from any fan-valley system of the world, has been recorded from over 0.22 million km sup(2) area located in the middle fan region of the Bay of Bengal. Their abundance is higher...

Numerical Simulation of single-stage axial fan operation under dusty flow conditions

Science.gov (United States)

Minkov, L. L.; Pikushchak, E. V.

2017-11-01

Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

School spirits: alcohol and collegiate sports fans.

Science.gov (United States)

Nelson, Toben F; Wechsler, Henry

2003-01-01

While studies have addressed alcohol use and related problems among college athletes, little is known about the drinking patterns of non-athletes who are sports fans. This study examines the relationship between alcohol use and interest in collegiate sports on two levels. First, do sports fans in college binge drink more and exhibit more negative alcohol-related outcomes than other students? Second, do colleges with large numbers of sports fans have higher rates of heavy drinking and accompanying secondhand effects affecting other students? The study analyzed the responses of a nationally representative sample of students who completed questionnaires in the spring of 1999 regarding their extracurricular activities and substance use. The responses of 3445 student sports fans were compared to those of 8405 students who were not sports fans. More sports fans drank alcohol, engaged in binge drinking, had a heavy drinking style and reported alcohol-related problems than nonfans. The percentage of sports fans at a school was associated with binge drinking rates and the secondhand effects. The implications for those working with college athletics and for alcohol prevention personnel are discussed. Copyright 2002 Elsevier Science Ltd.

Modeling of Broadband Liners Applied to the Advanced Noise Control Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.

2015-01-01

The broadband component of fan noise has grown in relevance with an increase in bypass ratio and incorporation of advanced fan designs. Therefore, while the attenuation of fan tones remains a major factor in engine nacelle acoustic liner design, the simultaneous reduction of broadband fan noise levels has received increased interest. As such, a previous investigation focused on improvements to an established broadband acoustic liner optimization process using the Advanced Noise Control Fan (ANCF) rig as a demonstrator. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom liner designs were carried through design, fabrication, and testing. This paper addresses a number of areas for further research identified in the initial assessment of the ANCF study. Specifically, incident source specification and uncertainty in some aspects of the predicted liner impedances are addressed. This information is incorporated in updated predictions of the liner performance and comparisons with measurement are greatly improved. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of various liner designs. This study also provides further confidence in the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

Quiet High Speed Fan II (QHSF II): Final Report

Science.gov (United States)

Kontos, Karen; Weir, Don; Ross, Dave

2012-01-01

This report details the aerodynamic, mechanical, structural design and fabrication of a Honey Engines Quiet High Speed Fan II (lower hub/tip ratio and higher specific flow than the Baseline I fan). This fan/nacelle system incorporates features such as advanced forward sweep and an advanced integrated fan/fan exit guide vane design that provides for the following characteristics: (1) Reduced noise at supersonic tip speeds, in comparison to current state-of-the-art fan technology; (2) Improved aeroelastic stability within the anticipated operating envelope; and (3) Aerodynamic performance consistent with current state-of-the-art fan technology. This fan was fabricated by Honeywell and tested in the NASA Glenn 9- by 15-Ft Low Speed Wind Tunnel for aerodynamic, aeromechanical, and acoustic performance.

Bydrage ta de kennis fan it libben, de persoan en it wurk fan Dr. Eeltsje Halbersma 1797-1858

NARCIS (Netherlands)

1946-01-01

It doel fan dizze dissertaesje is yn 'e earste pleats nij materiael to bringen oer Dr. Eeltsje. De wichtichste boarnen foar syn libben en syn wurk binne syn brieven oan Ds, Joast. Oant nou ta wie fan dy brieven mar in lyts bytsje bikend wurden, Dêrneist binne fansels ek de brieven fan Ds. Joast en

Variables and potential models for the bleaching of luminescence signals in fluvial environments

Science.gov (United States)

Gray, Harrison J.; Mahan, Shannon

2015-01-01

Luminescence dating of fluvial sediments rests on the assumption that sufficient sunlight is available to remove a previously obtained signal in a process deemed bleaching. However, luminescence signals obtained from sediment in the active channels of rivers often contain residual signals. This paper explores and attempts to build theoretical models for the bleaching of luminescence signals in fluvial settings. We present two models, one for sediment transported in an episodic manner, such as flood-driven washes in arid environments, and one for sediment transported in a continuous manner, such as in large continental scale rivers. The episodic flow model assumes that the majority of sediment is bleached while exposed to sunlight at the near surface between flood events and predicts a power-law decay in luminescence signal with downstream transport distance. The continuous flow model is developed by combining the Beer–Lambert law for the attenuation of light through a water column with a general-order kinetics equation to produce an equation with the form of a double negative exponential. The inflection point of this equation is compared with the sediment concentration from a Rouse profile to derive a non-dimensional number capable of assessing the likely extent of bleaching for a given set of luminescence and fluvial parameters. Although these models are theoretically based and not yet necessarily applicable to real-world fluvial systems, we introduce these ideas to stimulate discussion and encourage the development of comprehensive bleaching models with predictive power.

Truncated Groebner fans and lattice ideals

OpenAIRE

Lauritzen, Niels

2005-01-01

We outline a generalization of the Groebner fan of a homogeneous ideal with maximal cells parametrizing truncated Groebner bases. This "truncated" Groebner fan is usually much smaller than the full Groebner fan and offers the natural framework for conversion between truncated Groebner bases. The generic Groebner walk generalizes naturally to this setting by using the Buchberger algorithm with truncation on facets. We specialize to the setting of lattice ideals. Here facets along the generic w...

Field migration rates of tidal meanders recapitulate fluvial morphodynamics.

Science.gov (United States)

Finotello, Alvise; Lanzoni, Stefano; Ghinassi, Massimiliano; Marani, Marco; Rinaldo, Andrea; D'Alpaos, Andrea

2018-02-13

The majority of tidal channels display marked meandering features. Despite their importance in oil-reservoir formation and tidal landscape morphology, questions remain on whether tidal-meander dynamics could be understood in terms of fluvial processes and theory. Key differences suggest otherwise, like the periodic reversal of landscape-forming tidal flows and the widely accepted empirical notion that tidal meanders are stable landscape features, in stark contrast with their migrating fluvial counterparts. On the contrary, here we show that, once properly normalized, observed migration rates of tidal and fluvial meanders are remarkably similar. Key to normalization is the role of tidal channel width that responds to the strong spatial gradients of landscape-forming flow rates and tidal prisms. We find that migration dynamics of tidal meanders agree with nonlinear theories for river meander evolution. Our results challenge the conventional view of tidal channels as stable landscape features and suggest that meandering tidal channels recapitulate many fluvial counterparts owing to large gradients of tidal prisms across meander wavelengths. Copyright © 2018 the Author(s). Published by PNAS.

Fluvial hydrology and geomorphology of Monsoon-dominated Indian rivers

Directory of Open Access Journals (Sweden)

Vishwas S. Kale

2005-11-01

Full Text Available The Indian rivers are dominantly monsoon rainfed. As a result, their regime characteristics are dictated by the spatio-temporal variations in the monsoon rainfall. Although the rivers carry out most of the geomorphic work during 4-5 months of the monsoon season, the nature and magnitude of response to variations in the discharge and sediment load varies with the basin size and relief characteristics. Large monsoon floods play a role of great importance on all the rivers. This paper describes the hydrological and geomorphological characteristics of the two major fluvial systems of the Indian region, namely the Himalayan fluvial system and the Peninsular fluvial system. Large number of studies published so far indicate that there are noteworthy differences between the two river systems, with respect to river hydrology, channel morphology, sediment load and behaviour. The nature of alterations in the fluvial system due to increased human interference is also briefly mentioned. This short review demonstrates that there is immense variety of rivers in India. This makes India one of the best places to study rivers and their forms and processes.

Submarine fans: A critical retrospective (1950–2015

Directory of Open Access Journals (Sweden)

G. Shanmugam

2016-04-01

Full Text Available When we look back the contributions on submarine fans during the past 65 years (1950–2015, the empirical data on 21 modern submarine fans and 10 ancient deep-water systems, published by the results of the First COMFAN (Committee on FANs Meeting (Bouma et al., 1985a, have remained the single most significant compilation of data on submarine fans. The 1970s were the “heyday” of submarine fan models. In the 21st century, the general focus has shifted from submarine fans to submarine mass movements, internal waves and tides, and contourites. The purpose of this review is to illustrate the complexity of issues surrounding the origin and classification of submarine fans. The principal elements of submarine fans, composed of canyons, channels, and lobes, are discussed using nine modern case studies from the Mediterranean Sea, the Equatorial Atlantic, the Gulf of Mexico, the North Pacific, the NE Indian Ocean (Bay of Bengal, and the East Sea (Korea. The Annot Sandstone (Eocene–Oligocene, exposed at Peira-Cava area, SE France, which served as the type locality for the “Bouma Sequence”, was reexamined. The field details are documented in questioning the validity of the model, which was the basis for the turbidite-fan link. The 29 fan-related models that are of conceptual significance, developed during the period 1970–2015, are discussed using modern and ancient systems. They are: (1 the classic submarine fan model with attached lobes, (2 the detached-lobe model, (3 the channel-levee complex without lobes, (4 the delta-fed ramp model, (5 the gully-lobe model, (6 the suprafan lobe model, (7 the depositional lobe model, (8 the fan lobe model, (9 the ponded lobe model, (10 the nine models based on grain size and sediment source, (11 the four fan models based on tectonic settings, (12 the Jackfork debrite model, (13 the basin-floor fan model, (14 supercritical and subcritical fans, and (15 the three types of fan reservoirs. Each model is unique

30 CFR 57.8529 - Auxiliary fan systems

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fan systems 57.8529 Section 57.8529 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Underground Only § 57.8529 Auxiliary fan systems When auxiliary fan systems are used, such systems shall...

30 CFR 57.8525 - Main fan maintenance.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main fan maintenance. 57.8525 Section 57.8525 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Underground Only § 57.8525 Main fan maintenance. Main fans shall be maintained according to either the...

Morphometric differences in debris flow and mixed flow fans in eastern Death Valley, CA

Science.gov (United States)

Wasklewicz, T. A.; Whitworth, J.

2004-12-01

Geomorphological features are best examined through direct measurement and parameterization of accurate topographic data. Fine-scale data are therefore required to produce a complete set of elevation data. Airborne Laser Swath Mapping (ALSM) data provide high-resolution data over large spatially continuous areas. The National Center for Advanced Laser Mapping (NCALM) collected ALSM data for an area along the eastern side of Death Valley extending from slightly north of Badwater to Mormon Point. The raw ALSM data were post-processed and delivered by NCALM in one-meter grid nodes that we converted to one-meter raster data sets. ALSM data are used to assess variations in the dimensions of surficial features found in 32 alluvial fans (21 debris flow and 11 mixed flow fans). Planimetric curvature of the fan surfaces is used to develop a topographic signature to distinguish debris flow from mixed flow fans. These two groups of fans are identified from field analysis of near vertical exposures along channels as well as surficial exposures at proximal, medial, and distal fan locations. One group of fans exhibited debris flow characteristics (DF), while the second group contained a mixture of fluid and debris flows (MF). Local planimetric curvature of the alluvial fan surfaces was derived from the one-meter DEM. The local curvature data were reclassified into concave and convex features. This sequence corresponds to two broad classes of fan features: channels and interfluves. Thirty random points were generated inside each fan polygon. The length of the nearest concave-convex (channel-interfluve) couplet was measured at each point and the percentage of convex and concave pixels in a 10m box centered on the random point was also recorded. Plots and statistical analyses of the data show clear indication that local planimetric curvature can be used as a topographic signature to distinguish between the varying formative processes in alluvial fans. Significant differences in the

Turbofan gas turbine engine with variable fan outlet guide vanes

Science.gov (United States)

Wood, Peter John (Inventor); LaChapelle, Donald George (Inventor); Grant, Carl (Inventor); Zenon, Ruby Lasandra (Inventor); Mielke, Mark Joseph (Inventor)

2010-01-01

A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

Online Fan Fiction and Critical Media Literacy

Science.gov (United States)

Black, Rebecca W.

2010-01-01

This article explores English-language-learning (ELL) youths' engagement with popular media through composing and publicly posting stories in an online fan fiction writing space. Fan fiction is a genre that lends itself to critical engagement with media texts as fans repurpose popular media to design their own narratives. Analyses describe how…

Motivational variables that influence fan attendance in domestic ...

African Journals Online (AJOL)

A convenience sample of 180 fans was surveyed from a Gauteng based team. A factor analytical approach revealed seven dimensions of fan motivation, namely, ... marketing communication strategies in various aspects of fan attendance.

Preliminary Aerodynamic Investigation of Fan Rotor Blade Morphing

Science.gov (United States)

Tweedt, Daniel L.

2012-01-01

Various new technologies currently under development may enable controlled blade shape variability, or so-called blade morphing, to be practically employed in aircraft engine fans and compressors in the foreseeable future. The current study is a relatively brief, preliminary computational fluid dynamics investigation aimed at partially demonstrating and quantifying the aerodynamic potential of fan rotor blade morphing. The investigation is intended to provide information useful for near-term planning, as well as aerodynamic solution data sets that can be subsequently analyzed using advanced acoustic diagnostic tools, for the purpose of making fan noise comparisons. Two existing fan system models serve as baselines for the investigation: the Advanced Ducted Propulsor fan with a design tip speed of 806 ft/sec and a pressure ratio of 1.294, and the Source Diagnostic Test fan with a design tip speed of 1215 ft/sec and a pressure ratio of 1.470. Both are 22-in. sub-scale, low-noise research fan/nacelle models that have undergone extensive experimental testing in the 9- by 15-foot Low Speed Wind Tunnel at the NASA Glenn Research Center. The study, restricted to fan rotor blade morphing only, involves a fairly simple blade morphing technique. Specifically, spanwise-linear variations in rotor blade-section setting angle are applied to alter the blade shape; that is, the blade is linearly retwisted from hub to tip. Aerodynamic performance comparisons are made between morphed-blade and corresponding baseline configurations on the basis of equal fan system thrust, where rotor rotational speed for the morphed-blade fan is varied to change the thrust level for that configuration. The results of the investigation confirm that rotor blade morphing could be a useful technology, with the potential to enable significant improvements in fan aerodynamic performance. Even though the study is very limited in scope and confined to simple geometric perturbations of two existing fan

Fan Cart: The Next Generation

Science.gov (United States)

Lamore, Brian

2016-01-01

For years the fan cart has provided physics students with an excellent resource for exploring fundamental mechanics concepts such as acceleration, Newton's laws, impulse, momentum, work-energy, and energy conversions. "The Physics Teacher" has even seen some excellent do-it-yourself (DIY) fan carts and activities. If you are interested…

Forced Response Analysis of a Fan with Boundary Layer Inlet Distortion

Science.gov (United States)

Bakhle, Milind A.; Reddy, T. S. R.; Coroneos, Rula M.

2014-01-01

Boundary layer ingesting propulsion systems have the potential to significantly reduce fuel burn for future generations of commercial aircraft, but these systems must be designed to overcome the challenge of high dynamic stresses in fan blades due to forced response. High dynamic stresses can lead to high cycle fatigue failures. High-fidelity computational analysis of the fan aeromechanics is integral to an ongoing effort to design a boundary layer ingesting inlet and fan for a wind-tunnel test. An unsteady flow solution from a Reynoldsaveraged Navier Stokes analysis of a coupled inlet-fan system is used to calculate blade unsteady loading and assess forced response of the fan to distorted inflow. Conducted prior to the mechanical design of a fan, the initial forced response analyses performed in this study provide an early look at the levels of dynamic stresses that are likely to be encountered. For the boundary layer ingesting inlet, the distortion contains strong engine order excitations that act simultaneously. The combined effect of these harmonics was considered in the calculation of the forced response stresses. Together, static and dynamic stresses can provide the information necessary to evaluate whether the blades are likely to fail due to high cycle fatigue. Based on the analyses done, the overspeed condition is likely to result in the smallest stress margin in terms of the mean and alternating stresses. Additional work is ongoing to expand the analyses to off-design conditions, on-resonance conditions, and to include more detailed modeling of the blade structure.

Fan edits and the legacy of The Phantom Edit

Directory of Open Access Journals (Sweden)

Joshua Wille

2014-09-01

Full Text Available A fan edit can generally be defined as an alternative version of a film or television text created by a fan. It offers a different viewing experience, much as a song remix offers a different listening experience. The contemporary wave of fan edits has emerged during the remix zeitgeist of digital media and at a time when digital video editing technology has become more affordable and popular. The increasing number of alternative versions of films and the works of revisionist Hollywood filmmakers such as George Lucas have contributed to a greater public understanding of cinema as a fluid medium instead of one that exists in a fixed form. The Phantom Edit (2000, a seminal fan edit based on Lucas's Star Wars Episode I: The Phantom Menace (1999, inspired new ranks of fan editors. However, critics have misunderstood fan edits as merely the work of disgruntled fans. In order to provide a critical and historical basis for studies in fan editing as a creative practice, I examine previous interpretations of fan edits in the context of relevant contemporary works, and I use an annotated chronology of The Phantom Edit to trace its influence on subsequent fan editing communities and uncover their relationship with intellectual property disputes.

Degradation of the Mitchell River fluvial megafan by alluvial gully erosion increased by post-European land use change, Queensland, Australia

Science.gov (United States)

Shellberg, J. G.; Spencer, J.; Brooks, A. P.; Pietsch, T. J.

2016-08-01

Along low gradient rivers in northern Australia, there is widespread gully erosion into unconfined alluvial deposits of active and inactive floodplains. On the Mitchell River fluvial megafan in northern Queensland, river incision and fan-head trenching into Pleistocene and Holocene megafan units with sodic soils created the potential energy for a secondary cycle of erosion. In this study, rates of alluvial gully erosion into incipiently-unstable channel banks and/or pre-existing floodplain features were quantified to assess the influence of land use change following European settlement. Alluvial gully scarp retreat rates were quantified at 18 sites across the megafan using recent GPS surveys and historic air photos, demonstrating rapid increases in gully area of 1.2 to 10 times their 1949 values. Extrapolation of gully area growth trends backward in time suggested that the current widespread phase of gullying initiated between 1880 and 1950, which is post-European settlement. This is supported by young optically stimulated luminescence (OSL) dates of gully inset-floodplain deposits, LiDAR terrain analysis, historic explorer accounts of earlier gully types, and archival records of cattle numbers and land management. It is deduced that intense cattle grazing and associated disturbance concentrated in the riparian zones during the dry season promoted gully erosion in the wet season along steep banks, adjacent floodplain hollows and precursor gullies. This is a result of reduced native grass cover, increased physical disturbance of soils, and the concentration of water runoff along cattle tracks, in addition to fire regime modifications, episodic drought, and the establishment of exotic weed and grass species. Geomorphic processes operating over geologic time across the fluvial megafan predisposed the landscape to being pushed by land used change across an intrinsically close geomorphic threshold towards instability. The evolution of these alluvial gullies is discussed

Evaluating process origins of sand-dominated fluvial stratigraphy

Science.gov (United States)

Chamberlin, E.; Hajek, E. A.

2015-12-01

Sand-dominated fluvial stratigraphy is often interpreted as indicating times of relatively slow subsidence because of the assumption that fine sediment (silt and clay) is reworked or bypassed during periods of low accommodation. However, sand-dominated successions may instead represent proximal, coarse-grained reaches of paleo-river basins and/or fluvial systems with a sandy sediment supply. Differentiating between these cases is critical for accurately interpreting mass-extraction profiles, basin-subsidence rates, and paleo-river avulsion and migration behavior from ancient fluvial deposits. We explore the degree to which sand-rich accumulations reflect supply-driven progradation or accommodation-limited reworking, by re-evaluating the Castlegate Sandstone (Utah, USA) and the upper Williams Fork Formation (Colorado, USA) - two Upper Cretaceous sandy fluvial deposits previously interpreted as having formed during periods of relatively low accommodation. Both units comprise amalgamated channel and bar deposits with minor intra-channel and overbank mudstones. To constrain relative reworking, we quantify the preservation of bar deposits in each unit using detailed facies and channel-deposit mapping, and compare bar-deposit preservation to expected preservation statistics generated with object-based models spanning a range of boundary conditions. To estimate the grain-size distribution of paleo-sediment input, we leverage results of experimental work that shows both bed-material deposits and accumulations on the downstream side of bars ("interbar fines") sample suspended and wash loads of active flows. We measure grain-size distributions of bar deposits and interbar fines to reconstruct the relative sandiness of paleo-sediment supplies for both systems. By using these novel approaches to test whether sand-rich fluvial deposits reflect river systems with accommodation-limited reworking and/or particularly sand-rich sediment loads, we can gain insight into large

Blade Vibration Measurement System for Unducted Fans

Science.gov (United States)

Marscher, William

2014-01-01

With propulsion research programs focused on new levels of efficiency and noise reduction, two avenues for advanced gas turbine technology are emerging: the geared turbofan and ultrahigh bypass ratio fan engines. Both of these candidates are being pursued as collaborative research projects between NASA and the engine manufacturers. The high bypass concept from GE Aviation is an unducted fan that features a bypass ratio of over 30 along with the accompanying benefits in fuel efficiency. This project improved the test and measurement capabilities of the unducted fan blade dynamic response. In the course of this project, Mechanical Solutions, Inc. (MSI) collaborated with GE Aviation to (1) define the requirements for fan blade measurements; (2) leverage MSI's radar-based system for compressor and turbine blade monitoring; and (3) develop, validate, and deliver a noncontacting blade vibration measurement system for unducted fans.

FANS-3D Users Guide (ESTEP Project ER 201031)

Science.gov (United States)

2016-08-01

TECHNICAL DOCUMENT 3293 August 2016 FANS -3D User’s Guide (ESTEP Project ER-201031) Pei-Fang Wang SSC Pacific Hamn-Ching...1.1 THEORY AND NUMERICAL ALGORITHM OF FANS CODE ............................................. 1 2. FANS -3D SOFTWARE DOCUMENTATION AND EXECUTION...5 3. FANS -3D CODE PARALLELIZATION

Neural bases of ingroup altruistic motivation in soccer fans.

Science.gov (United States)

Bortolini, Tiago; Bado, Patrícia; Hoefle, Sebastian; Engel, Annerose; Zahn, Roland; de Oliveira Souza, Ricardo; Dreher, Jean-Claude; Moll, Jorge

2017-11-23

Humans have a strong need to belong to social groups and a natural inclination to benefit ingroup members. Although the psychological mechanisms behind human prosociality have extensively been studied, the specific neural systems bridging group belongingness and altruistic motivation remain to be identified. Here, we used soccer fandom as an ecological framing of group membership to investigate the neural mechanisms underlying ingroup altruistic behaviour in male fans using event-related functional magnetic resonance. We designed an effort measure based on handgrip strength to assess the motivation to earn money (i) for oneself, (ii) for anonymous ingroup fans, or (iii) for a neutral group of anonymous non-fans. While overlapping valuation signals in the medial orbitofrontal cortex (mOFC) were observed for the three conditions, the subgenual cingulate cortex (SCC) exhibited increased functional connectivity with the mOFC as well as stronger hemodynamic responses for ingroup versus outgroup decisions. These findings indicate a key role for the SCC, a region previously implicated in altruistic decisions and group affiliation, in dovetailing altruistic motivations with neural valuation systems in real-life ingroup behaviour.

Unsteady Landscapes: Climatic and Tectonic Controls on Fluvial Terrace Formation

Science.gov (United States)

Clubb, F. J.; Mudd, S. M.

2017-12-01

Fluvial terraces are common landforms throughout mountainous regions which represent abandoned remnants of active river systems and their floodplains. The formation of these landforms points to a fundamental unsteadiness in the incision rate of the fluvial network, providing important information on channel response to climatic, tectonic, and base-level forcing, sediment storage and dynamics within mountainous systems, and the relative importance of lateral and vertical incision rates. In his 1877 Report on the Geology of the Henry Mountains, G.K. Gilbert suggested that strath terraces may form due to climatically-driven increase in sediment supply, causing armouring of the channel bed and hindering vertical incision. An alternative hypothesis suggests that strath terraces may be preserved through progressive tectonic uplift or base-level fall. These different formation mechanisms should result in varying distribution of terrace elevations along channels: if terraces are formed through climate-driven variations in sediment supply, we might expect that terrace elevations would be random, whereas progressive fluvial incision should result in a series of terraces with a systematic elevation pattern. Here we test alternative hypotheses for strath terrace formation using a new method for objectively and rapidly identifying terrace surfaces from digital elevation models (DEMs) over large spatial scales. Our new method identifies fluvial terraces using their gradient and elevation compared to the modern channel, thresholds of which are statistically calculated from the DEM and do not need to be set manually by the user. We use this method to extract fluvial terraces for every major river along the coast of California, and quantify their distribution and elevation along the fluvial long profile. Our results show that there is no systematic pattern in terrace elevations despite a well-constrained spatial variation in uplift rates, suggesting that terraces in this region do

Fluvial deposits as an archive of early human activity: Progress during the 20 years of the Fluvial Archives Group

Science.gov (United States)

Chauhan, Parth R.; Bridgland, David R.; Moncel, Marie-Hélène; Antoine, Pierre; Bahain, Jean-Jacques; Briant, Rebecca; Cunha, Pedro P.; Despriée, Jackie; Limondin-Lozouet, Nicole; Locht, Jean-Luc; Martins, Antonio A.; Schreve, Danielle C.; Shaw, Andrew D.; Voinchet, Pierre; Westaway, Rob; White, Mark J.; White, Tom S.

2017-06-01

Fluvial sedimentary archives are important repositories for Lower and Middle Palaeolithic artefacts throughout the 'Old World', especially in Europe, where the beginning of their study coincided with the realisation that early humans were of great antiquity. Now that many river terrace sequences can be reliably dated and correlated with the globally valid marine isotope record, potentially useful patterns can be recognized in the distribution of the find-spots of the artefacts that constitute the large collections that were assembled during the years of manual gravel extraction. This paper reviews the advances during the past two decades in knowledge of hominin occupation based on artefact occurrences in fluvial contexts, in Europe, Asia and Africa. As such it is an update of a comparable review in 2007, at the end of IGCP Project no. 449, which had instigated the compilation of fluvial records from around the world during 2000-2004, under the auspices of the Fluvial Archives Group. An overarching finding is the confirmation of the well-established view that in Europe there is a demarcation between handaxe making in the west and flake-core industries in the east, although on a wider scale that pattern is undermined by the increased numbers of Lower Palaeolithic bifaces now recognized in East Asia. It is also apparent that, although it seems to have appeared at different places and at different times in the later Lower Palaeolithic, the arrival of Levallois technology as a global phenomenon was similarly timed across the area occupied by Middle Pleistocene hominins, at around 0.3 Ma.

Procedure for Balancing an Air Distribution System with Decentralised Fans

DEFF Research Database (Denmark)

Gunner, Amalie; Hultmark, Göran; Vorre, Anders

2015-01-01

flawed. This paper presents a new procedure for balancing of CAV systems in combination with decentralised fans. The new system was based on replacing the balancing dampers with decentralised fans. By replacing the balancing dampers with decentralised fans, airflows can be balanced by adjusting the speed...... of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan...... pressure requirements the fan was dimensioned for the branch with the least pressure resistance. The decentralised fans then provided sufficient pressure to overcome the exact resistance in the corresponding branch. The results show that by using decentralised fans in duct systems instead of dampers...

A 3D microtomographic system with stacked fan-beam geometry

International Nuclear Information System (INIS)

Kohlbrenner, Adrian; Haemmerle, Stefan; Laib, Andres; Rueegsegger, Peter

2000-01-01

The move from 2D to 3D analysis, and the increase in spatial resolution characterize recent improvements in CT-based structure assessment. A new desktop micro-CT system with high scanning speed has been developed. The instrument makes use of a novel multiple fan-beam technique: radiation from a line-focus X-ray tube is divided into a stack of fan-beams by a foil collimator with a 30 μm pitch. The stacked fan-beam geometry allows to design compact CT scanners with a source-to-detector distance of only 18 cm. The complete system fits into a standard 19 in. rack. Image reconstruction is based on standard fan-beam algorithms, which eliminates the difficulties and limitations associated with cone-beam reconstruction. The detector comprises a low-noise area CCD sensor, a fiber-optic light guide and a scintillator screen. A complete examination requires 2 min only. The new micro-CT system has a voxel size of 20x20x26 μm 3 . Each 3D image contains a quarter of a billion voxels or a multiple of it. Samples up to 20 mm in diameter and up to 40 mm in length can be imaged. The instrument can be operated in a normal lab environment

30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the applicable...

Martian Fluvial Conglomerates at Gale Crater

Science.gov (United States)

Williams, R. M. E.; Grotzinger, J. P.; Dietrich, W. E.; Gupta, S.; Sumner, D. Y.; Wiens, R. C.; Mangold, N.; Malin, M. C.; Edgett, K. S.; Maurice, S.; Forni, O.; Gasnault, O.; Ollila, A.; Newsom, H. E.; Dromart, G.; Palucis, M. C.; Yingst, R. A.; Anderson, R. B.; Herkenhoff, K. E.; Le Mouélic, S.; Goetz, W.; Madsen, M. B.; Koefoed, A.; Jensen, J. K.; Bridges, J. C.; Schwenzer, S. P.; Lewis, K. W.; Stack, K. M.; Rubin, D.; Kah, L. C.; Bell, J. F.; Farmer, J. D.; Sullivan, R.; Van Beek, T.; Blaney, D. L.; Pariser, O.; Deen, R. G.; Kemppinen, Osku; Bridges, Nathan; Johnson, Jeffrey R.; Minitti, Michelle; Cremers, David; Edgar, Lauren; Godber, Austin; Wadhwa, Meenakshi; Wellington, Danika; McEwan, Ian; Newman, Claire; Richardson, Mark; Charpentier, Antoine; Peret, Laurent; King, Penelope; Blank, Jennifer; Weigle, Gerald; Schmidt, Mariek; Li, Shuai; Milliken, Ralph; Robertson, Kevin; Sun, Vivian; Baker, Michael; Edwards, Christopher; Ehlmann, Bethany; Farley, Kenneth; Griffes, Jennifer; Miller, Hayden; Newcombe, Megan; Pilorget, Cedric; Rice, Melissa; Siebach, Kirsten; Stolper, Edward; Brunet, Claude; Hipkin, Victoria; Léveillé, Richard; Marchand, Geneviève; Sobrón Sánchez, Pablo; Favot, Laurent; Cody, George; Steele, Andrew; Flückiger, Lorenzo; Lees, David; Nefian, Ara; Martin, Mildred; Gailhanou, Marc; Westall, Frances; Israël, Guy; Agard, Christophe; Baroukh, Julien; Donny, Christophe; Gaboriaud, Alain; Guillemot, Philippe; Lafaille, Vivian; Lorigny, Eric; Paillet, Alexis; Pérez, René; Saccoccio, Muriel; Yana, Charles; Aparicio, Carlos Armiens; Caride Rodríguez, Javier; Carrasco Blázquez, Isaías; Gómez Gómez, Felipe; Elvira, Javier Gómez; Hettrich, Sebastian; Lepinette Malvitte, Alain; Marín Jiménez, Mercedes; Frías, Jesús Martínez; Soler, Javier Martín; Torres, F. Javier Martín; Molina Jurado, Antonio; Sotomayor, Luis Mora; Muñoz Caro, Guillermo; Navarro López, Sara; González, Verónica Peinado; García, Jorge Pla; Rodriguez Manfredi, José Antonio; Planelló, Julio José Romeral; Alejandra Sans Fuentes, Sara; Sebastian Martinez, Eduardo; Torres Redondo, Josefina; O'Callaghan, Roser Urqui; Zorzano Mier, María-Paz; Chipera, Steve; Lacour, Jean-Luc; Mauchien, Patrick; Sirven, Jean-Baptiste; Manning, Heidi; Fairén, Alberto; Hayes, Alexander; Joseph, Jonathan; Squyres, Steven; Thomas, Peter; Dupont, Audrey; Lundberg, Angela; Melikechi, Noureddine; Mezzacappa, Alissa; DeMarines, Julia; Grinspoon, David; Reitz, Günther; Prats, Benito; Atlaskin, Evgeny; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri; Kahanpää, Henrik; Kauhanen, Janne; Paton, Mark; Polkko, Jouni; Schmidt, Walter; Siili, Tero; Fabre, Cécile; Wray, James; Wilhelm, Mary Beth; Poitrasson, Franck; Patel, Kiran; Gorevan, Stephen; Indyk, Stephen; Paulsen, Gale; Bish, David; Schieber, Juergen; Gondet, Brigitte; Langevin, Yves; Geffroy, Claude; Baratoux, David; Berger, Gilles; Cros, Alain; Uston, Claude d.; Lasue, Jérémie; Lee, Qiu-Mei; Meslin, Pierre-Yves; Pallier, Etienne; Parot, Yann; Pinet, Patrick; Schröder, Susanne; Toplis, Mike; Lewin, Éric; Brunner, Will; Heydari, Ezat; Achilles, Cherie; Oehler, Dorothy; Sutter, Brad; Cabane, Michel; Coscia, David; Szopa, Cyril; Robert, François; Sautter, Violaine; Nachon, Marion; Buch, Arnaud; Stalport, Fabien; Coll, Patrice; François, Pascaline; Raulin, François; Teinturier, Samuel; Cameron, James; Clegg, Sam; Cousin, Agnès; DeLapp, Dorothea; Dingler, Robert; Jackson, Ryan Steele; Johnstone, Stephen; Lanza, Nina; Little, Cynthia; Nelson, Tony; Williams, Richard B.; Jones, Andrea; Kirkland, Laurel; Treiman, Allan; Baker, Burt; Cantor, Bruce; Caplinger, Michael; Davis, Scott; Duston, Brian; Fay, Donald; Hardgrove, Craig; Harker, David; Herrera, Paul; Jensen, Elsa; Kennedy, Megan R.; Krezoski, Gillian; Krysak, Daniel; Lipkaman, Leslie; McCartney, Elaina; McNair, Sean; Nixon, Brian; Posiolova, Liliya; Ravine, Michael; Salamon, Andrew; Saper, Lee; Stoiber, Kevin; Supulver, Kimberley; Van Beek, Jason; Zimdar, Robert; French, Katherine Louise; Iagnemma, Karl; Miller, Kristen; Summons, Roger; Goesmann, Fred; Hviid, Stubbe; Johnson, Micah; Lefavor, Matthew; Lyness, Eric; Breves, Elly; Dyar, M. Darby; Fassett, Caleb; Blake, David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence; Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda; Keely, Leslie; McKay, Christopher; Bleacher, Lora; Brinckerhoff, William; Choi, David; Conrad, Pamela; Dworkin, Jason P.; Eigenbrode, Jennifer; Floyd, Melissa; Freissinet, Caroline; Garvin, James; Glavin, Daniel; Harpold, Daniel; Mahaffy, Paul; Martin, David K.; McAdam, Amy; Pavlov, Alexander; Raaen, Eric; Smith, Michael D.; Stern, Jennifer; Tan, Florence; Trainer, Melissa; Meyer, Michael; Posner, Arik; Voytek, Mary; Anderson, Robert C.; Aubrey, Andrew; Beegle, Luther W.; Behar, Alberto; Brinza, David; Calef, Fred; Christensen, Lance; Crisp, Joy A.; DeFlores, Lauren; Feldman, Jason; Feldman, Sabrina; Flesch, Gregory; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki, Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy; Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John J.; Spanovich, Nicole; de la Torre Juarez, Manuel; Vasavada, Ashwin R.; Webster, Christopher R.; Yen, Albert; Archer, Paul Douglas; Cucinotta, Francis; Jones, John H.; Ming, Douglas; Morris, Richard V.; Niles, Paul; Rampe, Elizabeth; Nolan, Thomas; Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve; Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Vaniman, David; Leshin, Laurie; Cleghorn, Timothy; Huntress, Wesley; Manhès, Gérard; Hudgins, Judy; Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Grant, John; Vicenzi, Edward; Wilson, Sharon A.; Bullock, Mark; Ehresmann, Bent; Hamilton, Victoria; Hassler, Donald; Peterson, Joseph; Rafkin, Scot; Zeitlin, Cary; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya; Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov, Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin, Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey; Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; McLennan, Scott; Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Lee, Ella Mae; Sucharski, Robert; Hernández, Miguel Ángel de Pablo; Blanco Ávalos, Juan José; Ramos, Miguel; Kim, Myung-Hee; Malespin, Charles; Plante, Ianik; Muller, Jan-Peter; González, Rafael Navarro; Ewing, Ryan; Boynton, William; Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna; Kortmann, Onno; Williams, Amy; Lugmair, Günter; Wilson, Michael A.; Jakosky, Bruce; Zunic, Tonci Balic; Frydenvang, Jens; Kinch, Kjartan; Stipp, Susan Louise Svane; Boyd, Nick; Campbell, John L.; Gellert, Ralf; Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha; Owen, Tobias; Rowland, Scott; Savijärvi, Hannu; Boehm, Eckart; Böttcher, Stephan; Burmeister, Sönke; Guo, Jingnan; Köhler, Jan; García, César Martín; Mellin, Reinhold Mueller; Schweingruber, Robert Wimmer; McConnochie, Timothy; Benna, Mehdi; Franz, Heather; Bower, Hannah; Brunner, Anna; Blau, Hannah; Boucher, Thomas; Carmosino, Marco; Atreya, Sushil; Elliott, Harvey; Halleaux, Douglas; Rennó, Nilton; Wong, Michael; Pepin, Robert; Elliott, Beverley; Spray, John; Thompson, Lucy; Gordon, Suzanne; Williams, Joshua; Vasconcelos, Paulo; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie; Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond; McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Arvidson, Raymond; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan; Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.

2013-05-01

Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.

Image reconstruction from multiple fan-beam projections

International Nuclear Information System (INIS)

Jelinek, J.; Overton, T.R.

1984-01-01

Special-purpose third-generation fan-beam CT systems can be greatly simplified by limiting the number of detectors, but this requires a different mode of data collection to provide a set of projections appropriate to the required spatial resolution in the reconstructed image. Repeated rotation of the source-detector fan, combined with shift of the detector array and perhaps offset of the source with respect to the fan's axis after each 360 0 rotation(cycle), provides a fairly general pattern of projection space filling. The authors' investigated the problem of optimal data-collection geometry for a multiple-rotation fan-beam scanner and of corresponding reconstruction algorithm

A supersonic fan equipped variable cycle engine for a Mach 2.7 supersonic transport

Science.gov (United States)

Tavares, T. S.

1985-01-01

The concept of a variable cycle turbofan engine with an axially supersonic fan stage as powerplant for a Mach 2.7 supersonic transport was evaluated. Quantitative cycle analysis was used to assess the effects of the fan inlet and blading efficiencies on engine performance. Thrust levels predicted by cycle analysis are shown to match the thrust requirements of a representative aircraft. Fan inlet geometry is discussed and it is shown that a fixed geometry conical spike will provide sufficient airflow throughout the operating regime. The supersonic fan considered consists of a single stage comprising a rotor and stator. The concept is similar in principle to a supersonic compressor, but differs by having a stator which removes swirl from the flow without producing a net rise in static pressure. Operating conditions peculiar to the axially supersonic fan are discussed. Geometry of rotor and stator cascades are presented which utilize a supersonic vortex flow distribution. Results of a 2-D CFD flow analysis of these cascades are presented. A simple estimate of passage losses was made using empirical methods.

NASA ISS Portable Fan Assembly Acoustics

Science.gov (United States)

Boone, Andrew; Allen, Christopher S.; Hess, Linda F.

2018-01-01

The Portable Fan Assembly (PFA) is a variable speed fan that can be used to provide additional ventilation inside International Space Station (ISS) modules as needed for crew comfort or for enhanced mixing of the ISS atmosphere. This fan can also be configured with a Shuttle era lithium hydroxide (LiOH) canister for CO2 removal in confined areas partially of fully isolated from the primary Environmental Control and Life Support System (ECLSS) on ISS which is responsible for CO2 removal. This report documents noise emission levels of the PFA at various speed settings and configurations. It also documents the acoustic attenuation effects realized when circulating air through the PFA inlet and outlet mufflers and when operating in its CO2 removal configuration (CRK) with a LiOH canister (sorbent bed) installed over the fan outlet.

Utilization of alternatives fuels in a fluvial convoy; Utilizacao de combustiveis alternativos em um comboio fluvial

Energy Technology Data Exchange (ETDEWEB)

Padovezi, Carlos D; Giraldo, Arnaldo

1987-12-31

This work presents the results of tests performed with ethanol and methanol in a fluvial convoy in Tiete river, Sao Paulo State - Southeast Brazil. It also outlines a comparison and evaluation methodology. 9 figs., 3 tabs.

Utilization of alternatives fuels in a fluvial convoy; Utilizacao de combustiveis alternativos em um comboio fluvial

Energy Technology Data Exchange (ETDEWEB)

Padovezi, Carlos D.; Giraldo, Arnaldo

1986-12-31

This work presents the results of tests performed with ethanol and methanol in a fluvial convoy in Tiete river, Sao Paulo State - Southeast Brazil. It also outlines a comparison and evaluation methodology. 9 figs., 3 tabs.

Depositional Architecture of Late Pleistocene-Holocene Coastal Alluvial-fan System in the Coastal Range, Taiwan

Science.gov (United States)

Chen, S. T.; Chen, W. S.

2016-12-01

Since late Pleistocene, the Coastal Range (Philippine Sea plate) collided and overridden on the Central Range (Eurasian Plate) along the Longitudinal Valley Fault. Therefore, the Coastal Range is exposed widely the late Pleistocene-Holocene marine and fluvial terraces caused by the tectonic uplift. Based on the estimation of paleosea-level elevations (Δh), depositional paleodepth, altitude distribution of Holocene deposits (D), altitude of outcrops (H), and 14C dating of marine deposits (t), the uplift rate (=(Δh+H +d-D)/t) is about 5-10 mm/yr in the southern Coastal Range. In this study, we suggest through field logging that the deposits can be divided into alluvial, foreshore (intertidal), shoreface, and offshore environments. In Dulan area in the southern Coastal Range, the uplift rate was 6-7 mm/yr during 16,380-10,000 cal yr BP and 3-4 mm/yr after 7,000 cal yr BP. Results from the Dulan Coastal alluvial-fan system can be divided into five depositional stages: (1) 16,380-14,300 cal yr BP: The rate of global sea level rise (SLR) has averaged about 6-7 mm/yr, similar to the tectonic uplift rate. In this stage, the bedrock was eroded and formed a wide wave-cut platform. (2) 14,300-10,000 cal yr BP: SLR of about 14 mm/yr that was faster than tectonic uplift rate of 6-7 mm/yr. As a result of transgression, the beach-lagoon deposits about 5 m thick were unconformably overlain on the wave-cut platform. (3) 10,000-8,200 cal yr BP: The ongoing sea level rise (SLR: 11 mm/yr), the lagoon deposits were overlain by an offshore slump deposits representing a gradual deepening of the depositional environment. (4) 8,200-7,930 cal yr BP (SLR: 6-7 mm/yr): The tectonic uplift rate may occur at similar SLR. The alluvial-fan deposits have prograded over the shallow marine deposits. (5) After 7,000 cal yr BP (SLR: 1-0 mm/yr): SLR was much slower than tectonic uplift rate of 3-4 mm/yr. Thus, Holocene marine terraces are extensively developed in the coastal region, showing that the

Design and evaluation of an aeroacoustic wind tunnel for measurement of axial flow fans.

Science.gov (United States)

Bilka, M; Anthoine, J; Schram, C

2011-12-01

An anechoic wind tunnel dedicated to fan self-noise studies has been designed and constructed at the von Karman Institute The multi-chamber, mass flow driven design allows for all fan performance characteristics, aerodynamic quantities (e.g., wake turbulence measurements), and acoustic properties to be assessed in the same facility with the same conditions. The acoustic chamber performance is assessed using the optimum reference method and found to be within the ISO 3745 standards down to 150 Hz for pure tone and broadband source mechanisms. The additional influence of installation effects of an aerodynamic inlet was found to create a scattered sound field only near the source location, while still providing good anechoic results at more distant sound pressure measurement positions. It was found to have inflow properties, span-wise uniformity, and low turbulence intensity, consistent with those desired for fan self-noise studies. © 2011 Acoustical Society of America

Performance Calculations for a Boundary-Layer-Ingesting Fan Stage from Sparse Measurements

Science.gov (United States)

Hirt, Stefanie M.; Wolter, John D.; Arend, David J.; Hearn, Tristan A.; Hardin, Larry W.; Gazzaniga, John A.

2018-01-01

A test of the Boundary Layer Ingesting-Inlet / Distortion-Tolerant Fan was completed in NASA Glenn's 8-Foot by 6-Foot supersonic wind tunnel. Inlet and fan performance were measured by surveys using a set of rotating rake arrays upstream and downstream of the fan stage. Surveys were conducted along the 100 percent speed line and a constant exit corrected flow line passing through the aerodynamic design point. These surveys represented only a small fraction of the data collected during the test. For other operating points, data was recorded as snapshots without rotating the rakes which resulted in a sparser set of recorded data. This paper will discuss analysis of these additional, lower measurement density data points to expand our coverage of the fan map. Several techniques will be used to supplement the snapshot data at test conditions where survey data also exists. The supplemented snapshot data will be compared with survey results to assess the quality of the approach. Effective methods will be used to analyze the data set for which only snapshots exist.

Fan relationship management in football - going beyond traditional product offerings to win the hearts of fans

DEFF Research Database (Denmark)

Cortsen, Kenneth

2015-01-01

The management and control of fan relations should go beyond a football club’s traditional product and service offerings and touch the important experiential side of the football economy. This will create a stronger platform to optimize ROI, ROE and ROO relating to different fan segments....

Dynamic and Implications of Football Fans' Club and Fans ...

African Journals Online (AJOL)

DrNneka

As spectator in football game for example, human beings are known to fragment into fans groups. ..... since respondents identified performance as the main motivating factor in their selection of supporting teams ... directional. They are supports ...

Landform Evolution Modeling of Specific Fluvially Eroded Physiographic Units on Titan

Science.gov (United States)

Moore, J. M.; Howard, A. D.; Schenk, P. M.

2015-01-01

Several recent studies have proposed certain terrain types (i.e., physiographic units) on Titan thought to be formed by fluvial processes acting on local uplands of bedrock or in some cases sediment. We have earlier used our landform evolution models to make general comparisons between Titan and other ice world landscapes (principally those of the Galilean satellites) that we have modeled the action of fluvial processes. Here we give examples of specific landscapes that, subsequent to modeled fluvial work acting on the surfaces, produce landscapes which resemble mapped terrain types on Titan.

Evaluation of the Appropriate Washout Period Following Fan Therapy for Dyspnea in Patients With Advanced Cancer: A Pilot Study.

Science.gov (United States)

Kako, Jun; Morita, Tatsuya; Yamaguchi, Takuhiro; Sekimoto, Asuko; Kobayashi, Masamitsu; Kinoshita, Hiroya; Ogawa, Asao; Zenda, Sadamoto; Uchitomi, Yosuke; Inoguchi, Hironobu; Matsushima, Eisuke

2018-02-01

To clarify the duration required for dyspnea to return to baseline severity after fan therapy, to evaluate whether fan-to-legs therapy or no fan therapy would be a suitable control therapy, and to investigate changes in patients' face surface temperature after fan therapy. In this pilot study, all participants received 3 interventions in the following order: no fan, fan to legs, and fan to face. Participants used a fan for 5 minutes, and they scored their dyspnea at 10-minute intervals for 60 minutes or until the score had returned to its baseline value, whichever occurred first. Nine patients with advanced cancer admitted to a palliative care unit were included; they had dyspnea at rest and rated its severity as at least 3 points on a 0- to 10-point numerical rating scale. Descriptive statistics and the Wilcoxon signed rank test were used to analyze the data. All patients completed the study. Of the 9 participants, 6 experienced a clinical benefit from using a fan to their faces. Of these patients, only 2 participants' (2 of 6) dyspnea scores returned to baseline by the end of the 60-minute assessment period after exposure to fan-to-face therapy. In fan-to-legs and no fan settings, there was no change in the dyspnea scores. There were significant differences between the baseline face surface temperature and that after fan-to-face and fan-to-legs settings. When using a crossover design to investigate the effect of fan therapy on dyspnea, 1 hour is an insufficient washout period.

30 CFR 75.310 - Installation of main mine fans.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of main mine fans. 75.310 Section... mine fans. (a) Each main mine fan shall be— (1) Installed on the surface in an incombustible housing... that gives a signal at the mine when the fan either slows or stops. A responsible person designated by...

K-pop Reception and Participatory Fan Culture in Austria

Directory of Open Access Journals (Sweden)

Sang-Yeon Sung

2013-12-01

Full Text Available K-pop’s popularity and its participatory fan culture have expanded beyond Asia and become significant in Europe in the past few years. After South Korean pop singer Psy’s “Gangnam Style” music video topped the Austrian chart in October 2012, the number and size of K-pop events in Austria sharply increased, with fans organizing various participatory events, including K-pop auditions, dance festivals, club meetings, quiz competitions, dance workshops, and smaller fan-culture gatherings. In the private sector, longtime fans have transitioned from participants to providers, and in the public sector, from observers to sponsors. Through in-depth interviews with event organizers, sponsors, and fans, this article offers an ethnographic study of the reception of K-pop in Europe that takes into consideration local interactions between fans and Korean sponsors, perspectives on the genre, patterns of social integration, and histories. As a case study, this research stresses the local situatedness of K-pop fan culture by arguing that local private and public sponsors and fans make the reception of K-pop different in each locality. By exploring local scenes of K-pop reception and fan culture, the article demonstrates the rapidly growing consumption of K-pop among Europeans and stresses multidirectional understandings of globalization.

Plate-fin array cooling using a finger-like piezoelectric fan

International Nuclear Information System (INIS)

Shyu, Jin-Cherng; Syu, Jhih-Zong

2014-01-01

In this study, the heat transfer of a plate-fin array cooled by a vibrating finger-like piezoelectric fan comprising four flexible rectangular blades was investigated. The results indicated that the heat transfer enhancement of the fin array cooled by a vibrating piezoelectric fan at x/L = 0.5 and H = 5 mm ranged between 1.5 and 3.3, regardless of the fin array orientation. However, the heat transfer enhancement caused by a fan being placed at either edge of the fin array yielded a dissimilar result between both of the fin array orientations because of the superimposed effects of the boundary layer development and the air flow induced by the fan. This dissimilarity was especially noticeable when the piezoelectric fan was composed of aluminum blades to accommodate the moderate Reynolds number. In addition to the Reynolds number, the ratio of the fan blade vibration envelope to the source area determined the Nu number of the piezoelectric fan-cooled fin array. This design enhanced the fin array heat transfer and reduced cooler volume by embedding multiple vibrating beams into the fin array. -- Highlights: • Heat transfer of a piezoelectric fan-cooled plate-fin array was investigated. • Effects of fan position, fan height and fan material on heat transfer were examined. • Similar heat transfer enhancement range was shown for both fin array orientations. • Fin heat transfer with a running Al fan at x = 0 was higher than that at x = 0.25L. • Besides fan Reynolds number, the area ratio also determined Nu of the fin array

"Emotions-Only" versus "Special People": Genre in fan discourse

Directory of Open Access Journals (Sweden)

Louisa Ellen Stein

2008-09-01

Full Text Available This essay looks at genre as a complex set of discursive threads running unevenly through production, TV text, and fan reception. Through a case study of the reception of fan favorite Roswell, this essay interrogates the role of genre in spectatorship. In its mixing of teen and science fiction elements, Roswell trod upon contested generic spaces, eliciting strong reaction from its viewers. Connections between genre and gender came to the fore, as producer commentary linked science fiction with male audiences and teen romance with female audiences. Fans responded with analyses that greatly complicated and at times overtly rejected industrial suppositions regarding the gendered work of genre. Through these fan conversations, we can witness the complexity of genre as discursive thread moving through not only TV texts but also multivariant fan responses. I intend this essay to work at two levels. My analysis of fan responses to Roswell models the possibilities of a close study of genre discourse. At the same time, my case study probes the nature of genre in fan engagement, as genre discourses intersect with other fan concerns such as character identification, perceptions of textual quality, and questions of gender representation. While we cannot necessarily look to fan accounts for proof of how viewers engage with genre, they do tell us how fans frame their engagement with genre, how they incorporate genre into their performance of fannishness, and how they perform and thus enact genre itself as a shared cultural process.

Riparian shrub metal concentrations and growth in amended fluvial mine tailings

Science.gov (United States)

Fluvial mine tailing deposition has caused extensive riparian damage throughout the western United States. Willows are often used for fluvial mine tailing revegetation, but some species accumulate excessive metal concentrations which could be detrimental to browsers. In a greenhouse experiment, gr...

Morphology of fluvial levee series along a river under human influence, Maros River, Hungary

Science.gov (United States)

Kiss, Tímea; Balogh, Márton; Fiala, Károly; Sipos, György

2018-02-01

The development and morphometry of fluvial levees reflect the connection between channel and overbank processes, which can be altered by various human activities. The aims of this study are to investigate the morphology and spatial characteristics of fluvial levees and evaluate the role of some local- and catchment-scale human activities on their medium-term (150 years) development. This study applies LiDAR data along a 53-km-long reach of the Maros River in Hungary. Six fluvial levee types are identified based on the beginning and end of their evolution. These levee types were generated by local nineteenth century channel regulation works (cutoffs) and mid-twentieth century channel narrowing, which was caused by gravel mining and water impoundment in the upstream sections. However, other human activities also influenced the development of active fluvial levees because their horizontal evolution could have been limited by embanked flood-protection levees or the widening of low-lying floodplain benches that were generated by channel narrowing. Additionally, revetment constructions influenced their vertical parameters as higher fluvial levees developed along the fixed banks. Generally, the older active fluvial levees are wider, while the younger active levees are narrower with steeper slopes but not always lower. On the low-lying floodplain levels (benches), the youngest fluvial levees evolved quite rapidly and consist of coarser material. Currently, only 9.8- to 38-year return-period floods could cover the fluvial levees, contributing to their evolution. This fact and the development of fluvial levee series with two-three members reflect a gradual decoupling of the channel from the floodplain.

Fan filmmaking and copyright in a global world: Warhammer 40,000 fan films and the case of Damnatus

Directory of Open Access Journals (Sweden)

John Walliss

2010-09-01

Full Text Available The last decade has witnessed a proliferation, both online and off-line, of films produced by amateurs inspired by mainstream films, TV shows, and novels. As with much other fan production, fan films exist in, at best, a legally gray area since they are produced by amateurs, rather than by the media companies that own the copyrights to the films and novels that provide both their inspiration and settings. I examine the phenomenon of fan filmmaking, focusing on films produced by fans of the Warhammer 40,000 (W40K tabletop battle game. In particular, I examine the case of Damnatus: The Enemy Within (Damnatus: Feind Im Innern, 2005, a German-made fan film set in the W40K universe, which was banned from release by the game's rights holder, the UK company Games Workshop, in 2007. Damnatus offers an interesting case study in both the ongoing struggle between rights holders and textual poachers and the tensions that can exist between different legal understandings of copyright in an increasingly globalized world.

Rating behavior of football fans by Internet

Directory of Open Access Journals (Sweden)

Dawid Szczygielski

2017-02-01

Full Text Available The aim of this article was to present the opinion of Internet users for football fans and their behavior. The research method was used diagnostic survey research in the form of a survey computer. 102 people were tested mostly in the age of 21-25 years. The research can draw the following conclusions: (1 Football stadiums should be better secured and protected by the relevant departments, (2 The colors and club merchandise is not a reliable indicator of fan devotion of his team, (3 These are the fans, the fans are cheering for is a sacred thing, (4 All acts of devastation to property and vandalism in football stadiums should be severely punished.

c-fans and Newton polyhedra of algebraic varieties

International Nuclear Information System (INIS)

Kazarnovskii, B Ya

2003-01-01

To every algebraic subvariety of a complex torus there corresponds a Euclidean geometric object called a c-fan. This correspondence determines an intersection theory for algebraic varieties. c-fans form a graded commutative algebra with visually defined operations. The c-fans of algebraic varieties lie in the subring of rational c-fans. It seems that other subrings may be used to construct an intersection theory for other categories of analytic varieties. We discover a relation between an old problem in the theory of convex bodies (the so-called Minkowski problem) and the ring of c-fans. This enables us to define a correspondence that sends any algebraic curve to a convex polyhedron in the space of characters of the torus

Heavy mineral analyses as a powerful tool in fluvial geomorphology

Science.gov (United States)

von Suchodoletz, Hans; Gärtner, Andreas; Faust, Dominik

2014-05-01

The Marneuli depression is a tectonic sub-basin of the Transcaucasian depression in eastern Georgia, filled with several decametres of fluvial, lacustrine and aeolian Quaternary sediments. In order to reconstruct past landscape evolution of the region we studied Late Quaternary fluvial sediments found along several rivers that flow through that depression. Whereas Holocene river sediments could generally easily be assigned to corresponding rivers, this was not always the case for older fluvial sediments. For this reason, we studied the heavy mineral contents of five recent rivers and of four sedimentary deposits of potential precursors. A total of 4088 analysed heavy mineral grains enabled us to set up the characteristic heavy mineral distribution pattern for each sample. Using these data, we were able to reconstruct the most likely source areas of the Late Pleistocene fluvial sediments and to link them with the catchment areas of recent rivers. This allowed us to identify and to substantiate significant Late Quaternary river diversions that could at least partly be assigned to ongoing tectonic processes.

Source of marine turbidites on the Andaman-Nicobar Islands: Nicobar Fan, Bengal Fan or paleo-Irrawaddy?

Science.gov (United States)

Carter, A.

2017-12-01

Marine turbidites from an axially fed submarine fan are intermittently exposed across the entire chain of the Andaman-Nicobar Islands. Known as the Andaman Flysch (AF) and loosely assigned to the Paleogene, it has been proposed that these rocks are sourced from the Himalaya and thus provide a unique window into early stages of orogenesis. Where the turbidites came from has been subject to debate; they are either Bengal Fan or forearc deposits cut off from the Bengal Fan and possibly sourced from the Irrawaddy delta. Following recent IODP drilling in the eastern Indian Ocean (Expeditions 354 and 362) it is now possible resolve this by comparing the provenance of AF turbidites with the Bengal and Nicobar Fans. The Andaman Flysch can be traced as detached outcrops all along the western side of the main islands of Andaman over a strike length of more than 200 km. Exposures along the east coast are confined to South Andaman Island. Petrographic and geochemical data show a common continental crust signal with minor contributions from arc material. But, there are also differences whereby west coast sandstones show significantly higher quartz content and less feldspars and rock fragments. Staurolite is also present in all samples from the western side, but is absent from east coast samples. Both detrital zircon U-Pb and Bulk rock Nd data record the presence of arc material likely from Myanmar. Detrital zircon data from the Nicobar Fan match the Andaman turbidites and indicate sources from the Greater and Tethyan Himalaya mixed with sediment from the Burmese arc. Transfer of Irrawaddy derived sediment to the Nicobar Fan is ruled out as sediment transfer across the fore-arc to the west was restricted by the then exposed Yadana and M8 highs in the north and the Sewell and Alcock Rises to the south. Sediment isopachs of the Martaban back arc basin, the main north-south-oriented depocentre in the Andaman Sea related to the development of the Thanlwin -Irrawaddy delta system

Numerical Aerodynamic Evaluation and Noise Investigation of a Bladeless Fan

OpenAIRE

mohammad jafari; Hossein Afshin; Bijan Farhanieh; Hamidreza bozorgasareh

2015-01-01

Bladeless fan is a novel fan type that has no observable impeller, usually used for domestic applications. Numerical investigation of a Bladeless fan via Finite Volume Method was carried out in this study. The fan was placed in center of a 4×2×2m room and 473 Eppler airfoil profile was used as cross section of the fan. Performance and noise level of the fan by solving continuity and momentum equations as well as noise equations of Broadband Noise Source (BNS) and Ffowcs Williams a...

Advanced Subsonic Technology (AST) 22-Inch Low Noise Research Fan Rig Preliminary Design of ADP-Type Fan 3

Science.gov (United States)

Jeracki, Robert J. (Technical Monitor); Topol, David A.; Ingram, Clint L.; Larkin, Michael J.; Roche, Charles H.; Thulin, Robert D.

2004-01-01

This report presents results of the work completed on the preliminary design of Fan 3 of NASA s 22-inch Fan Low Noise Research project. Fan 3 was intended to build on the experience gained from Fans 1 and 2 by demonstrating noise reduction technology that surpasses 1992 levels by 6 dB. The work was performed as part of NASA s Advanced Subsonic Technology (AST) program. Work on this task was conducted in the areas of CFD code validation, acoustic prediction and validation, rotor parametric studies, and fan exit guide vane (FEGV) studies up to the time when a NASA decision was made to cancel the design, fabrication and testing phases of the work. The scope of the program changed accordingly to concentrate on two subtasks: (1) Rig data analysis and CFD code validation and (2) Fan and FEGV optimization studies. The results of the CFD code validation work showed that this tool predicts 3D flowfield features well from the blade trailing edge to about a chord downstream. The CFD tool loses accuracy as the distance from the trailing edge increases beyond a blade chord. The comparisons of noise predictions to rig test data showed that both the tone noise tool and the broadband noise tool demonstrated reasonable agreement with the data to the degree that these tools can reliably be used for design work. The section on rig airflow and inlet separation analysis describes the method used to determine total fan airflow, shows the good agreement of predicted boundary layer profiles to measured profiles, and shows separation angles of attack ranging from 29.5 to 27deg for the range of airflows tested. The results of the rotor parametric studies were significant in leading to the decision not to pursue a new rotor design for Fan 3 and resulted in recommendations to concentrate efforts on FEGV stator designs. The ensuing parametric study on FEGV designs showed the potential for 8 to 10 EPNdB noise reduction relative to the baseline.

14 CFR 33.27 - Turbine, compressor, fan, and turbosupercharger rotors.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine, compressor, fan, and... Turbine, compressor, fan, and turbosupercharger rotors. (a) Turbine, compressor, fan, and... affect turbine, compressor, fan, and turbosupercharger rotor structural integrity will not be exceeded in...

More air performance, enhanced energy efficiency. Plug Fans fit for the future; Mehr Luftleistung, hohe Energieeffizienz. Plug Fans fit fuer die Zukunft

Energy Technology Data Exchange (ETDEWEB)

Sigloch, Uwe; Muehleck, Ralf [ebm-papst, Mulfingen (Germany); Reiff, Ellen-Christine [Redaktionsbuero, Stutensee (Germany)

2011-08-15

The ErP directive 2009/125/EC demands a design of products for the European market according to pre-defined performance criteria. All fans with a performance between 125 W and 500 kW are affected by this directive. Ebm-papst Mulfingen GmbH and Co. KG (Mulfingen, Federal Republic of Germany) has developed and expanded the fan series Plug fans with Greentech EC technology in order to cover even higher air output ranges. Straight in the air technology and air conditioning systems a great potential of energy saving can be deduced with these fans. It is precisely in this area, the fans are operated with a long duty cycle.

CFD Models of a Serpentine Inlet, Fan, and Nozzle

Science.gov (United States)

Chima, R. V.; Arend, D. J.; Castner, R. S.; Slater, J. W.; Truax, P. P.

2010-01-01

Several computational fluid dynamics (CFD) codes were used to analyze the Versatile Integrated Inlet Propulsion Aerodynamics Rig (VIIPAR) located at NASA Glenn Research Center. The rig consists of a serpentine inlet, a rake assembly, inlet guide vanes, a 12-in. diameter tip-turbine driven fan stage, exit rakes or probes, and an exhaust nozzle with a translating centerbody. The analyses were done to develop computational capabilities for modeling inlet/fan interaction and to help interpret experimental data. Three-dimensional Reynolds averaged Navier-Stokes (RANS) calculations of the fan stage were used to predict the operating line of the stage, the effects of leakage from the turbine stream, and the effects of inlet guide vane (IGV) setting angle. Coupled axisymmetric calculations of a bellmouth, fan, and nozzle were used to develop techniques for coupling codes together and to investigate possible effects of the nozzle on the fan. RANS calculations of the serpentine inlet were coupled to Euler calculations of the fan to investigate the complete inlet/fan system. Computed wall static pressures along the inlet centerline agreed reasonably well with experimental data but computed total pressures at the aerodynamic interface plane (AIP) showed significant differences from the data. Inlet distortion was shown to reduce the fan corrected flow and pressure ratio, and was not completely eliminated by passage through the fan

Suspended sediment transport trough a large fluvial-tidal channel network

Science.gov (United States)

Wright, Scott A.; Morgan-King, Tara L.

2015-01-01

The confluence of the Sacramento and San Joaquin Rivers, CA, forms a large network of interconnected channels, referred to as the Sacramento-San Joaquin Delta (the Delta). The Delta comprises the transition zone from the fluvial influences of the upstream rivers and tidal influences of San Francisco Bay downstream. Formerly an extensive tidal marsh, the hydrodynamics and geomorphology of Delta have been substantially modified by humans to support agriculture, navigation, and water supply. These modifications, including construction of new channels, diking and draining of tidal wetlands, dredging of navigation channels, and the operation of large pumping facilities for distribution of freshwater from the Delta to other parts of the state, have had a dramatic impact on the physical and ecological processes within the Delta. To better understand the current physical processes, and their linkages to ecological processes, the USGS maintains an extensive network of flow, sediment, and water quality gages in the Delta. Flow gaging is accomplished through use of the index-velocity method, and sediment monitoring uses turbidity as a surrogate for suspended-sediment concentration. Herein, we present analyses of the transport and dispersal of suspended sediment through the complex network of channels in the Delta. The primary source of sediment to the Delta is the Sacramento River, which delivers pulses of sediment primarily during winter and spring runoff events. Upon reaching the Delta, the sediment pulses move through the fluvial-tidal transition while also encountering numerous channel junctions as the Sacramento River branches into several distributary channels. The monitoring network allows us to track these pulses through the network and document the dominant transport pathways for suspended sediment. Further, the flow gaging allows for an assessment of the relative effects of advection (the fluvial signal) and dispersion (from the tides) on the sediment pulses as they

16 CFR 305.13 - Labeling for ceiling fans.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Labeling for ceiling fans. 305.13 Section... Disclosures § 305.13 Labeling for ceiling fans. (a) Ceiling fans—(1) Content. Any covered product that is a ceiling fan shall be labeled clearly and conspicuously on the principal display panel with the following...

76 FR 50739 - Hung Ta Fan: Debarment Order

Science.gov (United States)

2011-08-16

...] Hung Ta Fan: Debarment Order AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The... (the FD&C Act) debarring Hung Ta Fan for a period of 5 years from importing articles of food or.... Fan was convicted of a felony under Federal law for conduct relating to the importation into the...

30 CFR 75.311 - Main mine fan operation.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fan operation. 75.311 Section 75.311... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.311 Main mine fan operation. (a) Main mine fans shall be continuously operated, except as otherwise approved in the ventilation plan, or when...

Fluvial response to the last Holocene rapid climate change in the Northwestern Mediterranean coastlands

Science.gov (United States)

Degeai, Jean-Philippe; Devillers, Benoît; Blanchemanche, Philippe; Dezileau, Laurent; Oueslati, Hamza; Tillier, Margaux; Bohbot, Hervé

2017-05-01

The variability of fluvial activity in the Northwestern Mediterranean coastal lowlands and its relationship with modes of climate change were analysed from the late 9th to the 18th centuries CE. Geochemical analyses were undertaken from a lagoonal sequence and surrounding sediments in order to track the fluvial inputs into the lagoon. An index based on the K/S and Rb/S ratios was used to evidence the main periods of fluvial activity. This index reveals that the Medieval Climate Anomaly (MCA) was a drier period characterized by a lower fluvial activity, while the Little Ice Age (LIA) was a wetter period with an increase of the river dynamics. Three periods of higher than average fluvial activity were evidenced at the end of the first millennium CE (ca. 900-950 cal yr CE), in the first half of the second millennium CE (ca. 1150-1550 cal yr CE), and during the 1600s-1700s CE (ca. 1650-1800 cal yr CE). The comparison of these fluvial periods with other records of riverine or lacustrine floods in Spain, Italy, and South of France seems to indicate a general increase in fluvial and flood patterns in the Northwestern Mediterranean in response to the climate change from the MCA to the LIA, although some episodes of flooding are not found in all records. Besides, the phases of higher than average fluvial dynamics are in good agreement with the North Atlantic cold events evidenced from records of ice-rafted debris. The evolution of fluvial activity in the Northwestern Mediterranean coastlands during the last millennium could have been driven by atmospheric and oceanic circulation patterns.

PLSS 2.5 Fan Design and Development

Science.gov (United States)

Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

2015-01-01

NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5.

An Alluvial Fan at Apollinaris Patera, Mars

OpenAIRE

Ghail, RC; Hutchison, JE

2003-01-01

Apollinaris Patera, Mars (7?S,173?E), is an intermediate sized volcano (~6 km high, 150 km diameter) with a large (200-km long) fan-like deposit on its southern flank. This fan is deeply incised and originates from a single breach in the rim of the summit caldera. New topographic and multispectral image data reveal that this fan is alluvial, implying a long-lived source of (volcaniclastic) sediment and water (probably from a caldera lake).

On Some Generalized Ky Fan Minimax Inequalities

Directory of Open Access Journals (Sweden)

Xianqiang Luo

2009-01-01

Full Text Available Some generalized Ky Fan minimax inequalities for vector-valued mappings are established by applying the classical Browder fixed point theorem and the Kakutani-Fan-Glicksberg fixed point theorem.

The modern Kaoping transient fan offshore SW Taiwan: Morphotectonics and development

Science.gov (United States)

Hsiung, Kan-Hsi; Yu, Ho-Shing; Chiang, Cheng-Shing

2018-01-01

Using bathymetry and seismic reflection profiles, this study examined and determined the transient nature of the Kaoping Fan located in the topographically complex slope offshore southwest Taiwan. Kaoping Fan is located west of the lower reach of the Kaoping Canyon at the lower Kaoping Slope, ranging from 2,200 to 3,000 m water depth, and has a relatively small areal extent restricted in the topographic lows confined by structural highs due to mud diapiric uplifting and thrust faulting. Kaoping Fan shows an asymmetrical triangular fan-shaped bathymetric feature elongated in an NW-SE direction but with a strong skew toward the east. The fan deposits consist of three main seismic facies: layered high-amplitude reflections in the upper section and stratified, parallel to sub-parallel low-amplitude reflections with variable continuity and channel fill facies in the lower section. In the absence of ground-truthing from core data, the seismic patterns suggest that the Kaoping Fan recorded the onset of channelized and over-bank deposits in the lower part and layered turbidite facies in the upper part subsequently. The development of the Kaoping Fan can be divided into three stages in terms of canyon activities and fan-feeding processes. Initially, Kaoping Fan was mainly fed by a point sediment source at the apex of the fan. Secondly, Kaoping Fan was maintained as a slope fan, mainly fed laterally by over-spilled sediments from the canyon. Finally, the Kaoping Canyon completely passes through the Kaoping Fan and supplies over-spilled sediments laterally, forming a transient fan with canyon incision and sediment by-passing. The accumulation of sediments and the growth of Kaoping Fan are primarily controlled by inherited complex paleo-topography and the evolution of Kaoping Canyon. The sediment delivery system of Kaoping Fan is characterized by lateral supply of over-spilling sediment flows and sediments bypassing to and beyond the base of slope. The Kaoping Fan together

A Paleogeographic and Depositional Model for the Neogene Fluvial Succession, Pishin Belt, Northwest Pakistan: Effect of Post Collisional Tectonics on Sedimentation in a Peripheral Foreland Setting

DEFF Research Database (Denmark)

Kasi, Aimal Khan; Kassi, Akhtar Muhammad; Umar, Muhammad

2018-01-01

. During the Early Miocene, subaerial sedimentation started after the final closure of the Katawaz Remnant Ocean. Based on detailed field data, twelve facies were recognized in Neogene successions exposed in the Pishin Belt. These facies were further organized into four facies associations i.e. channels......‐story sandstone and/or conglomerate channels, lateral accretion surfaces (point bars) and alluvial fans. Neogene sedimentation in the Pishin Belt was mainly controlled by active tectonism and thrusting in response to the oblique collision of the Indian Plate with the Afghan Block of the Eurasian Plate along......, crevasse splay, natural levee and floodplain facies associations. Facies associations and variations provided ample evidence to recognize a number of fluvial architectural components in the succession e.g., low‐sinuosity sandy braided river, mixed‐load meandering, high‐sinuosity meandering channels, single...

Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan

Science.gov (United States)

Jafari, Mohammad; Sojoudi, Atta; Hafezisefat, Parinaz

2017-03-01

Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated.

Simulation comparison between natural and hybrid ventilation by fans at night time for severe hot climate (Aswan, Egypt)

Energy Technology Data Exchange (ETDEWEB)

Rizk, A. [Department of Architectural Engineering, Faculty of Engineering, Tanta University, Tanta (Egypt); El-Deberky, A. [Department of Architecture, Faculty of Fine Arts, Minya University, Minya (Egypt); Guirguis, N. M. [Housing and Building Research Center, Cairo (Egypt)

2010-07-01

During the summer in Aswan, Egypt, indoor temperatures rise to a level exceeding thermal comfort. Due to the lag time of the building's envelope, temperature at night is higher inside than outside during the overheated period. The aim of this paper is to assess the effectiveness of ceiling and wall falls in lowering indoor air temperature at night. Computer simulations were carried out with ANSYS FLOTRAN computational fluid dynamic on a single room; 3 models were studied: natural ventilation, hybrid ventilation with a wall fan and hybrid ventilation with a ceiling fan. Results showed that hybrid ventilation fan is more effective in decreasing the temperature than natural cross ventilation alone and it was found that a wall fan is better than a ceiling fan. This study demonstrated that using hybrid ventilation with a side fan is the best option to reduce the air temperature in a room in Aswan, Egypt.

PLSS 2.5 Fan Design and Development

Science.gov (United States)

Converse, David; Carra, Michael; Quinn, Gregory; Chullen, Cinda

2015-01-01

NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from over five years ago. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0. It uses the same basic non-metallic can around the motor, but with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 loop. This allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds. Development of the fan also considered a shrouded impeller design that allows larger clearances for greater oxygen safety and better performance.

Development of a Fan for Future Space Suit Applications

Science.gov (United States)

Paul. Heather L.; Converse, David; Dionne, Steven; Moser, Jeff

2010-01-01

NASA's next generation space suit system will place new demands on the fan used to circulate breathing gas through the ventilation loop of the portable life support system. Long duration missions with frequent extravehicular activities (EVAs), the requirement for significant increases in reliability and durability, and a mission profile that imposes strict limits on weight, volume and power create the basis for a set of requirements that demand more performance than is available from existing fan designs. This paper describes the development of a new fan to meet these needs. A centrifugal fan was designed with a normal operating speed of approximately 39,400 rpm to meet the ventilation flow requirements while also meeting the aggressive minimal packaging, weight and power requirements. The prototype fan also operates at 56,000 rpm to satisfy a second operating condition associated with a single fan providing ventilation flow to two spacesuits connected in series. This fan incorporates a novel nonmetallic "can" to keep the oxygen flow separate from the motor electronics, thus eliminating ignition potential. The nonmetallic can enables a small package size and low power consumption. To keep cost and schedule within project bounds a commercial motor controller was used. The fan design has been detailed and implemented using materials and approaches selected to address anticipated mission needs. Test data is presented to show how this fan performs relative to anticipated ventilation requirements for the EVA portable life support system. Additionally, data is presented to show tolerance to anticipated environmental factors such as acoustics, shock, and vibration. Recommendations for forward work to progress the technology readiness level and prepare the fan for the next EVA space suit system are also discussed.

Developing a Composite Aquifer Vulnerability Assessment Model Combining DRASTIC with Agricultural Land Use in Choushui River Alluvial Fan, Central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Hsieh, Chih-Heng; Tsai, Cheng-Bin

2017-04-01

Aquifer vulnerability assessment is considered to be an effective tool in controlling potential pollution which is critical for groundwater management. The Choushui River alluvial fan, located in central Taiwan, is an agricultural area with complex crop patterns and various irrigation schemes, which increased the difficulties in groundwater resource management. The aim of this study is to propose an integrated methodology to assess shallow groundwater vulnerability by including land-use impact on groundwater potential pollution. The original groundwater vulnerability methodology, DRASTIC, was modified by adding a land-use parameter in order to assess groundwater vulnerability under intense agricultural activities. To examine the prediction capacity of pollution for the modified DRASTIC model, various risk categories of contamination potentials were compared with observed nitrate-N obtained from groundwater monitoring network. It was found that for the original DRASTIC vulnerability map, some areas with low nitrate-N concentrations are covered within the high vulnerability areas, especially in the northern part of mid-fan areas, where rice paddy is the main crop and planted for two crop seasons per year. The low nitrate-N contamination potential of rice paddies may be resulted from the denitrification in the reduced root zone. By reducing the rating for rice paddies, the modified model was proved to be capable of increasing the precise of prediction in study area. The results can provide a basis for groundwater monitoring network design and effective preserve measures formulation in the mixed agricultural area. Keyword:Aquifer Vulnerability, Groundwater, DRASTIC, Nitrate-N

Modeling plan-form deltaic response to changes in fluvial sediment supply

NARCIS (Netherlands)

Nienhuis, J.H.; Ashton, A.D.; Roos, Pieter C.; Hulscher, Suzanne J.M.H.; Giosan, L.; Kranenburg, W.M.; Horstman, E.M.; Wijnberg, K.M.

2012-01-01

This study focuses on the effects of changes in fluvial sediment supply on the plan-form shape of wave-dominated deltas. We apply a one-line numerical shoreline model to calculate shoreline evolution after (I) elimination and (II) time-periodic variation of fluvial input. Model results suggest four

Aerodynamic modelling and optimization of axial fans

Energy Technology Data Exchange (ETDEWEB)

Noertoft Soerensen, Dan

1998-01-01

A numerically efficient mathematical model for the aerodynamics of low speed axial fans of the arbitrary vortex flow type has been developed. The model is based on a blade-element principle, whereby the rotor is divided into a number of annular stream tubes. For each of these stream tubes relations for velocity, pressure and radial position are derived from the conservation laws for mass, tangential momentum and energy. The equations are solved using the Newton-Raphson methods, and solutions converged to machine accuracy are found at small computing costs. The model has been validated against published measurements on various fan configurations, comprising two rotor-only fan stages, a counter-rotating fan unit and a stator-rotor stator stage. Comparisons of local and integrated properties show that the computed results agree well with the measurements. Optimizations have been performed to maximize the mean value of fan efficiency in a design interval of flow rates, thus designing a fan which operates well over a range of different flow conditions. The optimization scheme was used to investigate the dependence of maximum efficiency on 1: the number of blades, 2: the width of the design interval and 3: the hub radius. The degree of freedom in the choice of design variable and constraints, combined with the design interval concept, provides a valuable design-tool for axial fans. To further investigate the use of design optimization, a model for the vortex shedding noise from the trailing edge of the blades has been incorporated into the optimization scheme. The noise emission from the blades was minimized in a flow rate design point. Optimizations were performed to investigate the dependence of the noise on 1: the number of blades, 2: a constraint imposed on efficiency and 3: the hub radius. The investigations showed, that a significant reduction of noise could be achieved, at the expense of a small reduction in fan efficiency. (EG) 66 refs.

30 CFR 75.313 - Main mine fan stoppage with persons underground.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fan stoppage with persons underground... mine fan stoppage with persons underground. (a) If a main mine fan stops while anyone is underground and the ventilating quantity provided by the fan is not maintained by a back-up fan system— (1...

30 CFR 77.212 - Draw-off tunnel ventilation fans; installation.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Draw-off tunnel ventilation fans; installation... UNDERGROUND COAL MINES Surface Installations § 77.212 Draw-off tunnel ventilation fans; installation. When fans are used to ventilate draw-off tunnels the fans shall be: (a) Installed on the surface; (b...

Shaler: in situ analysis of a fluvial sedimentary deposit on Mars

Science.gov (United States)

Edgar, Lauren; Gupta, Sanjeev; Rubin, David M.; Lewis, Kevin W.; Kocurek, Gary A.; Anderson, Ryan; Bell, James F.; Dromart, Gilles; Edgett, Kenneth S.; Grotzinger, John P.; Hardgrove, Craig; Kah, Linda C.; LeVeille, Richard A.; Malin, Michael C.; Mangold, Nicholas; Milliken, Ralph E.; Minitti, Michelle; Palucis, Marisa C.; Rice, Melissa; Rowland, Scott K.; Schieber, Juergen; Stack, Kathryn M.; Sumner, Dawn Y.; Wiens, Roger C.; Williams, Rebecca M.E.; Williams, Amy J.

2018-01-01

This paper characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time, and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground-based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars Science Laboratory Curiosity rover provide an opportunity to reconstruct at fine scale the sedimentary architecture and palaeomorphology of a fluvial environment on Mars. This work describes the grain size, texture, and sedimentary facies of the Shaler outcrop, reconstructs the bedding architecture, and analyses cross-stratification to determine palaeocurrents. On the basis of bedset geometry and inclination, grain-size distribution, and bedform migration direction, this study concludes that the Shaler outcrop likely records the accretion of a fluvial barform. The majority of the outcrop consists of large-scale trough cross-bedding of coarse sand and granules. Palaeocurrent analyses and bedform reconstruction indicate that the beds were deposited by bedforms that migrated towards the northeast, across the surface of a bar that migrated southeast. Stacked cosets of dune cross-bedding suggest aggradation of multiple bedforms, which provides evidence for short periods of sustained flow during Shaler deposition. However, local evidence for aeolian reworking and the presence of potential desiccation cracks within the outcrop suggests that fluvial deposition may have been intermittent. The uppermost strata at Shaler are distinct in terms of texture and chemistry, and are inferred to record deposition from a different sediment dispersal system with a contrasting provenance. The outcrop as a whole is a testament to the availability of liquid water on the surface of Mars in its early history.

High-Resolution Geologic Mapping of Martian Terraced Fan Deposits

Science.gov (United States)

Wolak, J. M.; Patterson, A. B.; Smith, S. D.; Robbins, N. N.

2018-06-01

This abstract documents our initial progress (year 1) mapping terraced fan features on Mars. Our objective is to investigate the role of fluids during fan formation and produce the first high-resolution geologic map (1:18k) of a terraced fan.

Aerodynamic Modelling and Optimization of Axial Fans

DEFF Research Database (Denmark)

Sørensen, Dan Nørtoft

A numerically efficient mathematical model for the aerodynamics oflow speed axial fans of the arbitrary vortex flow type has been developed.The model is based on a blade-element principle, whereby therotor is divided into a number of annular streamtubes.For each of these streamtubes relations......-Raphson method, andsolutions converged to machine accuracy are found at small computing costs.The model has been validated against published measurementson various fan configurations,comprising two rotor-only fan stages, a counter-rotatingfan unit and a stator-rotor-stator stage.Comparisons of local...... and integrated propertiesshow that the computed results agree well with the measurements.Integrating a rotor-only version of the aerodynamic modelwith an algorithm for numerical designoptimization, enables the finding of an optimum fan rotor.The angular velocity of the rotor, the hub radius and the spanwise...

The Lower Cretaceous Way Group of northern Chile: An alluvial fan-fan delta complex

Science.gov (United States)

Flint, S.; Clemmey, H.; Turner, P.

1986-01-01

Alluvial fan sediments of the Lower Cretaceous Coloso Basin in northern Chile were deposited in a half-graben and derived from andesitic volcanics of a former island arc. Transport directions were towards the east, away from the present-day Peru-Chile trench. Grain flow, density modified grain flow and sheetflow processes were responsible for most of the sediment deposition with cohesive debris flows playing only a minor part. An early phase of conglomerate deposition (Coloso Formation) into a restricted basin records the transition from proximal fan facies with abundant grain flows and remobilized screes to mid-fan facies dominated by sheetflows. Stratiform copper mineralization near the top of the lower conglomerates is related to the unroofing of the Jurassic island arc. This mineralization comprises copper sulphide-cemented sands and gravels and formed by the reaction of mineralized detritus with diagenetic and hydrothermal solutions. A later phase of deposition (Lombriz Formation) includes sandstones, siltstones and conglomerates with a source area different from the Coloso Formation. This change in source may be related to strike-slip tectonics as the basin extended. The Lombriz conglomerates pass distally (eastwards) into red sandstones and purple siltstones with thin limestones deposited under marine conditions. This sequence is interpreted as a major fan delta complex. It passes conformably into marine carbonates of the Tableado Formation signifying the complete drowning of the basin in lower Cretaceous times.

The Right to Be a Fan

Science.gov (United States)

Gutierrez, Peter

2011-01-01

Reading experts have consistently cited the importance of independent reading, reading for pleasure, and fostering "a love of reading." Unfortunately, fanning the fire of fan readership is not so easy in the service of our clear-cut and standards-aligned curricula, except perhaps in small, carefully channeled doses. Moreover, the impetus for such…

The morphology, processes, and evolution of Monterey Fan: a revisit

Science.gov (United States)

Gardner, James V.; Bohannon, Robert G.; Field, Michael E.; Masson, Douglas G.

2010-01-01

Long-range (GLORIA) and mid-range (TOBI) sidescan imagery and seismic-reflection profiles have revealed the surface morphology and architecture of the complete Monterey Fan. The fan has not developed a classic wedge shape because it has been blocked for much of its history by Morro Fracture Zone. The barrier has caused the fan to develop an upper-fan and lower-fan sequence that are distinctly different from one another. The upper-fan sequence is characterized by Monterey and Ascension Channels and associated Monterey Channel-levee system. The lower-fan sequence is characterized by depositional lobes of the Ascension, Monterey, and Sur-Parkington-Lucia systems, with the Monterey depositional lobe being the youngest. Presently, the Monterey depositional lobe is being downcut because the system has reached a new, lower base level in the Murray Fracture Zone. A five-step evolution of Monterey Fan is presented, starting with initial fan deposition in the Late Miocene, about 5.5 Ma. This first stage was one of filling bathymetric lows in the oceanic basement in what was to become the upper-fan segment. The second stage involved filling the bathymetric low on the north side of Morro Fracture Zone, and probably not much sediment was transported beyond the fracture zone. The third stage witnessed sediment being transported around both ends of Morro Fracture Zone and initial sedimentation on the lower-fan segment. During the fourth stage Ascension Channel was diverted into Monterey Channel, thereby cutting off sedimentation to the Ascension depositional lobe.

Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

NARCIS (Netherlands)

de Haas, T.|info:eu-repo/dai/nl/374023190

2016-01-01

Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and

Fan-shaped antennas: Realization of wideband characteristics and generation of stop bands

Science.gov (United States)

Nakano, H.; Morishita, K.; Iitsuka, Y.; Mimaki, H.; Yoshida, T.; Yamauchi, J.

2008-08-01

This paper presents four fan-shaped antennas: U.S.-FAN, CROSS-FAN, CROSS-FAN-W, and CROSS-FAN-S. Each of these antennas stands upright above a ground plane, and has edges expressed by an exponential function and a circle function. The four antennas are investigated using frequencies from 1.5 GHz to 11 GHz. The CROSS-FAN is found to have a lower VSWR over a wide frequency band compared to the U.S.-FAN. The CROSS-FAN-W and CROSS-FAN-S are modified versions of the CROSS-FAN, each designed to have a stop band (a high VSWR frequency range) for interference cancellation. The stop band for the CROSS-FAN-W is controlled by a wire (total length 4Lwire) that connects the fan-shaped elements. The center frequency of the stop band fstop is close to the frequency corresponding to a wire segment length Lwire of half the wavelength. It is also found that the stop band in the CROSS-FAN-S can be controlled by four slots, one cut into each of the fan-shaped elements. The center frequency of the stop band fstop is close to the frequency corresponding to a slot length Lslot of one-quarter of the wavelength. Experimental work is performed to confirm the theoretical results, using the CROSS-FAN-S.

Silent cooling system with a double suction type centrifugal fan with backward blades; Ryosuikomi turbo fan wo mochiita teisoon engine reikyaku system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Funabashi, S. [Hitachi, Ltd., Tokyo (Japan); Nakamura, K. [Hitachi Construction Machinery Co. Ltd., Tokyo (Japan)

2000-04-25

We have developed a new cooling system for the engine of construction machinery. This system produces two different air flow routes by a double suction type centrifugal fan with backward blades. We first measured aerodynamic performance and sound level of the double suction type fan, which consists of two single suction type fans of different design, and compared these measurements to those of single suction type fans. Next, we installed the fan in a scale model of the new cooling system. The performance of this double suction type fan was different to that of a single suction type. It is considered that the effect of interaction of the exit flows from the two different fans caused this performance change. The test model installed in an engine compartment showed that this cooling system reduced the area of air inlets and outlets around the engine and did not cause re-circulation of cooling air. (author)

Sherlock (Holmes in Japanese (fan works [symposium

Directory of Open Access Journals (Sweden)

Lori Morimoto

2017-03-01

Full Text Available I explore the history of Japanese writing centered on Sherlock Holmes as a means of interrogating the 2014 BBC Sherlock pastiche John and Sherlock Casebook 1: Jon, zenchi renmei e iku (The stark naked league, written by Japanese Sherlockian Kitahara Naohiko for mainstream publication by the publishing house Hayakawa shobō. I argue that exploration of the Japanese (fan cultural contexts of Kitahara's book begins to reveal the limits of the Anglo-American-centered framework through which fan studies scholars explore fan/producer relationships.

Evolution of the alluvial fans of the Luo River in the Weihe Basin, central China, controlled by faulting and climate change - A reevaluation of the paleogeographical setting of Dali Man site

Science.gov (United States)

Rits, Daniël S.; van Balen, Ronald T.; Prins, Maarten A.; Zheng, Hongbo

2017-06-01

The Luo River is located in the southern part of the Chinese Loess Plateau and the northern part of the Weihe Basin, in Central China. In the basin it flows proximal to the site of the Luyang Wetland core, which is an important archive of climate change over the past 1 Myr in this region. In this paper, the contribution of the Luo River to the sedimentary record is analyzed by reconstructing the evolution of this river during the Middle to Late Pleistocene. It is argued that an alluvial fan of the Luo River has contributed to the sedimentary archive until approximately 200-240 ka. From this moment onwards, the fan became incised and terraces began to form. The formation of a new alluvial fan further downstream led to the disconnection of the Luo River from the Luyang Wetland core site. We propose that this series of events was caused by the displacement of an intra-basinal fault and the resultant faulting-forced folding, which caused increased relative subsidence, and thus increased sedimentation rates at the core site. Therefore, a complete sediment record in the 'Luyang Wetland' was preserved, despite the disconnection from the Luo River. The chronology of the fans and terraces was established using existing age control (U-series, ESR, OSL, pIRIR290 and magnetic susceptibility correlation), and through correlation of the loess-paleosol cover to marine isotope stages. Based on sedimentological characteristics of the fluvial sequence, we suggest that incision of the Luo River occurred in two steps. Small incisions took place at transitions to interglacials and the main incision phases occur at the transition from an interglacial to glacial climate. Due to the incision, basal parts of the oldest Luo River alluvial fan are exposed, and it is in one of these exposures that the famous Dali Man skull was retrieved. This study shows that the Dali Man did not live on a river terrace as previously thought, but on an aggrading alluvial fan, during wet, glacial conditions.

weiqiang fan

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics. WEIQIANG FAN. Articles written in Journal of Genetics. Volume 96 Issue 6 December 2017 pp 867-872 RESEARCH ARTICLE. A genetic variant in COL11A1 is functionally associated with lumbar disc herniation in Chinese population · WENJUN LIU GUISEN SUN LONGSHENG GUO ...

Review of noise reduction methods for centrifugal fans

Science.gov (United States)

Neise, W.

1981-11-01

Several methods for the reduction of centrifugal fan noise are presented, the most of which are aimed at a lower blade passage frequency level. The methods are grouped into five categories: casing modifications to increase the distance between impeller and cutoff, the introduction of a phase shift of the source pressure fluctuations, impeller modifications, radial clearance between impeller eye and inlet nozzle, and acoustical measures. Resonators mounted at the cutoff of centrifugal fans appear to be a highly efficient and simple means of reducing the blade passage tone, and the method can be used for new fan construction and existing installations without affecting the aerodynamic performance of the fan.

The performance of a centrifugal fan with enlarged impeller

International Nuclear Information System (INIS)

Li Chunxi; Song Lingwang; Jia Yakui

2011-01-01

Highlights: → The influence of impeller enlargement is evaluated numerically and experimentally. → Variation equations of the operation points for enlarged impellers are derived. → Impeller enlargement leads to louder fan noise due to reduced impeller-volute gap. - Abstract: The influence of enlarged impeller in unchanged volute on G4-73 type centrifugal fan performance is investigated in this paper. Comparisons are conducted between the fan with original impeller and two larger impellers with the increments in impeller outlet diameter of 5% and 10% respectively in the numerical and experimental investigations. The internal characteristics are obtained by the numerical simulation, which indicate there is more volute loss in the fan with larger impeller. Experiment results show that the flow rate, total pressure rise, shaft power and sound pressure level have increased, while the efficiency have decreased when the fan operates with larger impeller. Variation equations on the performance of the operation points for the fan with enlarged impellers are suggested. Comparisons between experiment results and the trimming laws show that the trimming laws for usual situation can predict the performance of the enlarged fan impeller with less error for higher flow rate, although the situation of application is not in agreement. The noise frequency analysis shows that higher noise level with the larger impeller fan is caused by the reduced impeller-volute gap.

The performance of a centrifugal fan with enlarged impeller

Energy Technology Data Exchange (ETDEWEB)

Li Chunxi, E-mail: leechunxi@163.com [School of Energy and Power Engineering, North China Electric Power University, 071003 Baoding, Hebei (China); Song Lingwang [School of Energy and Power Engineering, North China Electric Power University, 071003 Baoding, Hebei (China); Jia Yakui [Hebei Electric Power Design and Research Institute, 050031 Shijiazhuang, Hebei (China)

2011-08-15

Highlights: {yields} The influence of impeller enlargement is evaluated numerically and experimentally. {yields} Variation equations of the operation points for enlarged impellers are derived. {yields} Impeller enlargement leads to louder fan noise due to reduced impeller-volute gap. - Abstract: The influence of enlarged impeller in unchanged volute on G4-73 type centrifugal fan performance is investigated in this paper. Comparisons are conducted between the fan with original impeller and two larger impellers with the increments in impeller outlet diameter of 5% and 10% respectively in the numerical and experimental investigations. The internal characteristics are obtained by the numerical simulation, which indicate there is more volute loss in the fan with larger impeller. Experiment results show that the flow rate, total pressure rise, shaft power and sound pressure level have increased, while the efficiency have decreased when the fan operates with larger impeller. Variation equations on the performance of the operation points for the fan with enlarged impellers are suggested. Comparisons between experiment results and the trimming laws show that the trimming laws for usual situation can predict the performance of the enlarged fan impeller with less error for higher flow rate, although the situation of application is not in agreement. The noise frequency analysis shows that higher noise level with the larger impeller fan is caused by the reduced impeller-volute gap.

A history of RPGs: Made by fans; played by fans

Directory of Open Access Journals (Sweden)

Paul Mason

2012-09-01

Full Text Available I explore some aspects of the early history of tabletop role-playing games (RPGs that are perhaps not well known among media scholars, and which offer an alternative take on the idea of fan activity.

Single photon emission computed tomography by using fan beam collimator

International Nuclear Information System (INIS)

Akiyama, Yoshihisa

1992-01-01

A multislice fan beam collimator which has parallel collimation along the cephalic-caudul axis of a patient and converging collimation within planes that are perpendicular to that axis was designed for a SPECT system with a rotating scintillation camera, and it was constructed by the lead casting method which was developed in recent years. A reconstruction algorithm for fan beam SPECT was formed originally by combining the reconstruction algorithm of the parallel beam SPECT with that of the fan beam X-ray CT. The algorithm for fan beam SPECT was confirmed by means of computer simulation and a head phantom filled with diluted radionuclide. Not only 99m Tc but also 123 I was used as a radionuclide. A SPECT image with the fan beam collimator was compared with that of a parallel hole, low energy, high resolution collimator which was routinely used for clinical and research SPECT studies. Both system resolution and sensitivity of the fan beam collimator were ∼20% better than those of the parallel hole collimator. Comparing SPECT images obtained from fan beam collimator with those of parallel hole collimator, the SPECT images using fan beam collimator had far better resolution. A fan beam collimator is a useful implement for the SPECT study. (author)

Performance/Noise Optimization of Centrifugal Fan Using Response Surface Method

Energy Technology Data Exchange (ETDEWEB)

Shin, Donghui; Cheong, Cheolung [Pusan Nat’l Univ., Busan (Korea, Republic of); Heo Seung [Korea Aerospace Industries, Sacheon (Korea, Republic of); Kim, Tae-Hoon; Jung, Jiwon [LG Electronics, Seoul (Korea, Republic of)

2017-03-15

In this study, centrifugal fan blades used to circulate cold air inside a household refrigerator were optimized to achieve high performance and low noise by using the response surface method, which is frequently employed as an optimization algorithm when multiple independent variables affect one dependent variable. The inlet and outlet blade angles, and the inner radius, were selected as the independent variables. First, the fan blades were optimized to achieve the maximum volume flow rate. Based on this result, a prototype fan blade was manufactured using a 3-D printer. The measured P-Q curves confirmed the increased volume flow rate of the proposed fan. Then, the rotation speed of the new fan was decreased to match the P-Q curve of the existing fan. It was found that a noise reduction of 1.7 dBA could be achieved using the new fan at the same volume flow rate.

Performance/Noise Optimization of Centrifugal Fan Using Response Surface Method

International Nuclear Information System (INIS)

Shin, Donghui; Cheong, Cheolung; Heo Seung; Kim, Tae-Hoon; Jung, Jiwon

2017-01-01

In this study, centrifugal fan blades used to circulate cold air inside a household refrigerator were optimized to achieve high performance and low noise by using the response surface method, which is frequently employed as an optimization algorithm when multiple independent variables affect one dependent variable. The inlet and outlet blade angles, and the inner radius, were selected as the independent variables. First, the fan blades were optimized to achieve the maximum volume flow rate. Based on this result, a prototype fan blade was manufactured using a 3-D printer. The measured P-Q curves confirmed the increased volume flow rate of the proposed fan. Then, the rotation speed of the new fan was decreased to match the P-Q curve of the existing fan. It was found that a noise reduction of 1.7 dBA could be achieved using the new fan at the same volume flow rate.

Study on performance of centripetal fan, 1

International Nuclear Information System (INIS)

Ejiri, Eiji; Shirakura, Masaaki; Tagori, Tetsuo; Enomoto, Hisao.

1984-01-01

Centripetal fans are radial flow type fans which gather air from outer side into inner side. The construction is simple, and when heat exchangers are arranged around them, cooled air can be discharged upward only by connecting simple ducts, accordingly, centripetal fans are suitable to the ventilating fans for superlarge cooling towers of nuclear power plants. The static pressure rise is obtained only by the diffuser action of impellers, therefore, they are not suitable to pumps and compressors, and their use is limited only to fans. Centrifugal force exerts negative effect on static pressure rise, accordingly, the ratio of internal diameter/external diameter of impellers cannot be made very small. In this study, a small model with impeller diameter of 0.6 m was used, and its overall performance, the performance of moving blades in the range of stable operation, the rotating stall characteristics in the region of low flow rate, and the effect of side wind on the overall performance in outdoor use were examined. By changing the angle of inclination of entrance guide vanes, the range of stable operation was expanded, and the pressure coefficient and efficiency were increased. (Kako, I.)

Fan action and political participation on "The Colbert Report"

Directory of Open Access Journals (Sweden)

Marcus Schulzke

2012-06-01

Full Text Available The Colbert Report merges the increasingly popular political satire genre with fan activism. The result is that the fan community helps to construct Colbert's malleable character and demonstrates symbolic power through its willingness to act. The fans are usually a nonpartisan force, acting to produce entertainment rather than substantive political change. However, this can be politically meaningful, as the fans' projects promote collective action, parallel political activities like voting and protesting, and encourage critical thinking about political information.

Contemporary Conceptual Approaches in Fluvial Geomorphology

Directory of Open Access Journals (Sweden)

Mônica dos Santos Marçal

2016-06-01

Full Text Available Contemporary fluvial geomorphology faces challenging questions, especially as it goes by understanding the Late Holocene/Anthropocene period, which has repercussions today and are intrinsically important to understand the human river disturbance. Given the scale that physical rates operate in complex river systems, two conceptual paths were developed to analyze the spatial and temporal organization. The network view emphasizes controls on catchment-scale and a reach approach focuses on discontinuity and local controls. Fluvial geomorphology has seek to understand the organization of complex river systems from the integrated view of the continuity and discontinuity paradigm. This integrated approach has stimulated within the geomorphology, the emergence of new theoretical-methodological instruments. It is recognized that rivers management is an ongoing process, part of the socio-cultural development, which refers to both a social movement and scientific exercise.

The Conceptual Design of High Pressure Reversible Axial Tunnel Ventilation Fans

Directory of Open Access Journals (Sweden)

A. G. Sheard

2012-01-01

Full Text Available Tunnel ventilation fans, classically, must have the ability to both supply and extract air from a tunnel system, with the operator's choice dependent on the tunnel ventilation system's operating mode most appropriate at any given point in time. Consequently, tunnel ventilation fans must incorporate a reversible aerodynamic design which limits the maximum fan pressure rise. This paper presents three high pressure reversible fan concepts. These comprise a two-stage counter rotating fan, a single-stage high speed fan, and a two-stage fan with a single motor and impeller on each end of the motor shaft. The authors consider the relative merits of each concept. The third concept offers the most compact fan, transform, silencer, and damper package size. The authors discuss the mechanical design challenges that occur with a two-stage fan with a single motor and impeller on each end of the motor shaft. They present and consider a selected motor bearing arrangement and casing design for maintainability. Finally, the authors present both prototype fan and full-scale package aerodynamic and acoustic performance, before discussing the challenges presented by high temperature certification in accordance with the requirements of EN 12101-3: 2012.

Aeromechanics Analysis of a Boundary Layer Ingesting Fan

Science.gov (United States)

Bakhle, Milind A.; Reddy, T. S. R.; Herrick, Gregory P.; Shabbir, Aamir; Florea, Razvan V.

2013-01-01

Boundary layer ingesting propulsion systems have the potential to significantly reduce fuel burn but these systems must overcome the challe nges related to aeromechanics-fan flutter stability and forced response dynamic stresses. High-fidelity computational analysis of the fan a eromechanics is integral to the ongoing effort to design a boundary layer ingesting inlet and fan for fabrication and wind-tunnel test. A t hree-dimensional, time-accurate, Reynolds-averaged Navier Stokes computational fluid dynamics code is used to study aerothermodynamic and a eromechanical behavior of the fan in response to both clean and distorted inflows. The computational aeromechanics analyses performed in th is study show an intermediate design iteration of the fan to be flutter-free at the design conditions analyzed with both clean and distorte d in-flows. Dynamic stresses from forced response have been calculated for the design rotational speed. Additional work is ongoing to expan d the analyses to off-design conditions, and for on-resonance conditions.

Experimental Investigation of a Forward Swept Rotor in a Multistage Fan with Inlet Distortion

Directory of Open Access Journals (Sweden)

Aspi R. Wadia

2011-01-01

Full Text Available Previous studies of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep to multistage configurations. The experimental investigation compare two builds of an advanced two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs. The presence of the inlet guide vanes had a profound impact in lowering the two-stage fan's sensitivity with inlet distortion.

Fan-beam intensity modulated proton therapy.

Science.gov (United States)

Hill, Patrick; Westerly, David; Mackie, Thomas

2013-11-01

This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0-255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage. Overall, the sharp distal

Characterization of Composite Fan Case Resins

Science.gov (United States)

Dvoracek, Charlene M.

2004-01-01

The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

Modeling Long-Term Fluvial Incision : Shall we Care for the Details of Short-Term Fluvial Dynamics?

Science.gov (United States)

Lague, D.; Davy, P.

2008-12-01

Fluvial incision laws used in numerical models of coupled climate, erosion and tectonics systems are mainly based on the family of stream power laws for which the rate of local erosion E is a power function of the topographic slope S and the local mean discharge Q : E = K Qm Sn. The exponents m and n are generally taken as (0.35, 0.7) or (0.5, 1), and K is chosen such that the predicted topographic elevation given the prevailing rates of precipitation and tectonics stay within realistic values. The resulting topographies are reasonably realistic, and the coupled system dynamics behaves somehow as expected : more precipitation induces increased erosion and localization of the deformation. Yet, if we now focus on smaller scale fluvial dynamics (the reach scale), recent advances have suggested that discharge variability, channel width dynamics or sediment flux effects may play a significant role in controlling incision rates. These are not factored in the simple stream power law model. In this work, we study how these short- term details propagate into long-term incision dynamics within the framework of surface/tectonics coupled numerical models. To upscale the short term dynamics to geological timescales, we use a numerical model of a trapezoidal river in which vertical and lateral incision processes are computed from fluid shear stress at a daily timescale, sediment transport and protection effects are factored in, as well as a variable discharge. We show that the stream power law model might still be a valid model but that as soon as realistic effects are included such as a threshold for sediment transport, variable discharge and dynamic width the resulting exponents m and n can be as high as 2 and 4. This high non-linearity has a profound consequence on the sensitivity of fluvial relief to incision rate. We also show that additional complexity does not systematically translates into more non-linear behaviour. For instance, considering only a dynamical width

CONSUMER BEHAVIOUR TOWARDS ELECTRIC FANS

OpenAIRE

Inderpreet Singh

2017-01-01

The study of consumer behaviour develops great interest for consumers, students, scientists, and marketers. As consumers, we need insights into our own consumption related decisions: what we buy, why we buy, and how we buy. The aim of the study is to cover entire research about consumer behaviour towards electric fans and different factors affecting their buying decision. A sample of 200 consumers of electric fans is taken. Questionnaire has been analysed with the help of pie diagram & bar ch...

FACTORS INFLUENCING BRAND LOYALTY IN PROFESSIONAL SPORTS FANS

OpenAIRE

Yun-Tsan Lin; Chen-Hsien Lin

2008-01-01

Many researchers have provided comprehensive definitions for the term of brand loyalty and also examined the factors affecting brand loyalty with many empirical studies. But there is little research focusing on the brand loyalty of professional sports fans. The topic area about factors influencing brand loyalty in professional sports fans was identified because these fans bring significant financial benefits every year and stimulate economic growth in the United States. Although different con...

Booster fans : some considerations for their usage in underground coal mines

Energy Technology Data Exchange (ETDEWEB)

Gillies, S.; Slaughter, C. [Missouri Univ. of Science and Technology, Rolla, MO (United States); Calizaya, F. [Utah Univ., Salt Lake City, UT (United States); Wu, H.W. [Gillies Wu Mining Technology Pty Ltd., Brisbane, QLD (Australia)

2010-07-01

This paper reported on a study that investigated the conditions under which booster fans can be used safely and efficiently in underground coal mines. Booster fans are installed in series with a main surface fan and are used to boost the air pressure of the ventilation air passing through it. Several coal mining countries use booster fans, but in the United States, they are only used in metal/non-metal mines due to concerns of uncontrolled recirculation. This study investigated installations of booster fans in non-US underground coal mines where safe and efficient atmospheric conditions are achieved. The purpose was to collect reliable information on airway resistances and flow requirements typical in large US coal mines. The study showed that safe booster fan installations are found in both high and low gas conditions, and sometimes where workings are located at great depths. The interlocking systems within the booster fan can control the underground fans and avoid recirculation when surface fans are unexpectedly turned off. Another purpose of the study was to determine when booster fans become a more viable solution in coal mines due to increases in air requirements at higher production rates. It was concluded that a new fan selection algorithm to produce recirculation-free ventilation designs will be developed to enable US coal mine operators to develop ventilation designs to extract coal seams from depths greater than 1000 m. 17 refs., 1 fig.

30 CFR 57.22209 - Auxiliary fans (I-C mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans (I-C mines). 57.22209 Section 57... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22209 Auxiliary fans (I-C mines). Electric auxiliary fans shall be approved by MSHA under the applicable requirements of 30 CFR part 18...

Acoustic Measurements of an Uninstalled Spacecraft Cabin Ventilation Fan Prototype

Science.gov (United States)

Koch, L. Danielle; Brown, Clifford A.; Shook, Tony D.; Winkel, James; Kolacz, John S.; Podboy, Devin M.; Loew, Raymond A.; Mirecki, Julius H.

2012-01-01

Sound pressure measurements were recorded for a prototype of a spacecraft cabin ventilation fan in a test in the NASA Glenn Acoustical Testing Laboratory. The axial fan is approximately 0.089 m (3.50 in.) in diameter and 0.223 m (9.00 in.) long and has nine rotor blades and eleven stator vanes. At design point of 12,000 rpm, the fan was predicted to produce a flow rate of 0.709 cu m/s (150 cfm) and a total pressure rise of 925 Pa (3.72 in. of water) at 12,000 rpm. While the fan was designed to be part of a ducted atmospheric revitalization system, no attempt was made to throttle the flow or simulate the installed configuration during this test. The fan was operated at six speeds from 6,000 to 13,500 rpm. A 13-microphone traversing array was used to collect sound pressure measurements along two horizontal planes parallel to the flow direction, two vertical planes upstream of the fan inlet and two vertical planes downstream of the fan exhaust. Measurements indicate that sound at blade passing frequency harmonics contribute significantly to the overall audible noise produced by the fan at free delivery conditions.

Amateur mythographies: Fan fiction and the myth of myth

Directory of Open Access Journals (Sweden)

Ika Willis

2016-03-01

Full Text Available This paper draws on classical scholarship on myth in order to critically examine three ways in which scholars and fans have articulated a relationship between fan fiction and myth. These are (1 the notion of fan fiction as a form of folk culture, reclaiming popular story from corporate ownership; (2 the notion of myth as counterhegemonic, often feminist, discourse; (3 the notion of myth as a commons of story and a universal story world. I argue that the first notion depends on an implicit primitivizing of fan fiction and myth, which draws ultimately on the work of Gottfried von Herder in the 18th century and limits our ability to produce historically and politically nuanced understandings of fan fiction. The second notion, which is visible in the work of Henry Jenkins and Constance Penley, is more helpful because of its attention to the politics of narration. However, it is the third model of myth, as a universal story world, where we find the richest crossover between fan fiction's creative power and contemporary classical scholarship on myth, especially in relation to Sarah Iles Johnston's analysis of hyperserial narrative. I demonstrate this through some close readings of fan fiction from the Greek and Roman Mythology fandom on Archive of Our Own. I conclude the paper by extending Johnston's arguments to show that fan-fictional hyperseriality, specifically, can be seen as mythic because it intervenes not only in the narrative worlds of its source materials but also in the social world of its telling.

Case study of French and Spanish fan reception of Game of Thrones

Directory of Open Access Journals (Sweden)

Mélanie Bourdaa

2015-06-01

Full Text Available The reception of the American TV show Game of Thrones (2011– by French and Spanish fans and nonfans is addressed via a qualitative methodology, the goal of which is to understand how European viewers perceive themselves as fans and what it means for them to be fans. Analysis of characteristics of a specifically European reception helps us learn what fan studies tell us about fans and what fans really think about fandoms.

Experimental investigation of fluvial dike breaching due to flow overtopping

Science.gov (United States)

El Kadi Abderrezzak, K.; Rifai, I.; Erpicum, S.; Archambeau, P.; Violeau, D.; Pirotton, M.; Dewals, B.

2017-12-01

The failure of fluvial dikes (levees) often leads to devastating floods that cause loss of life and damages to public infrastructure. Overtopping flows have been recognized as one of the most frequent cause of dike erosion and breaching. Fluvial dike breaching is different from frontal dike (embankments) breaching, because of specific geometry and boundary conditions. The current knowledge on the physical processes underpinning fluvial dike failure due to overtopping remains limited. In addition, there is a lack of a continuous monitoring of the 3D breach formation, limiting the analysis of the key mechanisms governing the breach development and the validation of conceptual or physically-based models. Laboratory tests on breach growth in homogeneous, non-cohesive sandy fluvial dikes due to flow overtopping have been performed. Two experimental setups have been constructed, permitting the investigation of various hydraulic and geometric parameters. Each experimental setup includes a main channel, separated from a floodplain by a dike. A rectangular initial notch is cut in the crest to initiate dike breaching. The breach development is monitored continuously using a specific developed laser profilometry technique. The observations have shown that the breach develops in two stages: first the breach deepens and widens with the breach centerline being gradually shifted toward the downstream side of the main channel. This behavior underlines the influence of the flow momentum component parallel to the dike crest. Second, the dike geometry upstream of the breach stops evolving and the breach widening continues only toward the downstream side of the main channel. The breach evolution has been found strongly affected by the flow conditions (i.e. inflow discharge in the main channel, downstream boundary condition) and floodplain confinement. The findings of this work shed light on key mechanisms of fluvial dike breaching, which differ substantially from those of dam

Erosion and deposition on a debris-flow fan

Science.gov (United States)

Densmore, A. L.; Schuerch, P.; Rosser, N. J.; McArdell, B. W.

2011-12-01

The ability of a debris flow to entrain or deposit sediment controls the downstream evolution of flow volume, and ultimately dictates both the geomorphic impact of the flow and the potential hazard that it represents. Our understanding of the patterns of, and controls on, such flow volume changes remains extremely limited, however, partly due to a poor mechanistic grasp of the interactions between debris flows and their bed and banks. In addition, we lack a good understanding of the cumulative long-term effects of sequences of flows in a single catchment-fan system. Here we begin to address these issues by using repeated terrestrial laser scanning (TLS) to characterize the detailed surface change associated with the passage of multiple debris flows on the Illgraben fan, Switzerland. We calculate surface elevation change along a 300 m study reach, and from this derive the downfan rate of flow volume change, or lag rate; for comparison, we also derive the spatially-averaged lag rate over the entire ~2 km length of the fan. Lag rates are broadly comparable over both length scales, indicating that flow behavior does not vary significantly across the fan for most flows, but importantly we find that flow volume at the fan head is a poor predictor of volume at the fan toe. The sign and magnitude of bed elevation change scale with local flow depth; at flow depths 2 m. On the Illgraben fan, this depth corresponds to a basal shear stress of 3-4 kPa. Because flow depth is in part a function of channel cross-sectional topography, which varies strongly both within and between flows, this result indicates that erosion and deposition are likely to be highly dynamic. The dependence of flow volume change on both the channel topography and the flow history may thus complicate efforts to predict debris-flow inundation areas by simple flow routing. We then apply a 2d numerical model of debris-flow fan evolution to explore the key controls on debris-flow routing and topographic

Characterizing fluvial heavy metal pollutions under different rainfall conditions: Implication for aquatic environment protection.

Science.gov (United States)

Zhang, Lixun; Zhao, Bo; Xu, Gang; Guan, Yuntao

2018-09-01

Globally, fluvial heavy metal (HM) pollution has recently become an increasingly severe problem. However, few studies have investigated the variational characteristics of fluvial HMs after rain over long periods (≥1 year). The Dakan River in Xili Reservoir watershed (China) was selected as a case study to investigate pollution levels, influencing factors, and sources of HMs under different rainfall conditions during 2015 and 2016. Fluvial HMs showed evident spatiotemporal variations attributable to the coupled effects of pollution generation and rainfall diffusion. Fluvial HM concentrations were significantly associated with rainfall characteristics (e.g., rainfall intensity, rainfall amount, and antecedent dry period) and river flow, which influenced the generation and the transmission of fluvial HMs in various ways. Moreover, this interrelationship depended considerably on the HM type and particle size distribution. Mn, Pb, Cr, and Ni were major contributors to high values of the comprehensive pollution index; therefore, they should be afforded special attention. Additionally, quantitative source apportionment of fluvial HMs was conducted by combining principal component analysis with multiple linear regression and chemical mass balance models to obtain comprehensive source profiles. Finally, an environment-friendly control strategy coupling "source elimination" and "transport barriers" was proposed for aquatic environment protection. Copyright © 2018 Elsevier B.V. All rights reserved.

Experimental and Numerical Investigation of a 60cm Diameter Bladeless Fan

OpenAIRE

mohammad jafari; Hossein Afshin; Bijan Farhanieh; Hamidreza bozorgasareh

2016-01-01

Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoust...

D0 Cryo Ventilation Fan Controls and Monitoring

International Nuclear Information System (INIS)

Markley, D.

1990-01-01

This engineering note describes how exhaust fan 6 (EF-6) and exhaust fan 7 (EF-7) are controlled and monitored. Since these two fans are a vital link in the ODH safety system, they will be monitored, controlled and periodically operated by the programmable logic controller (PLC). If there should be a fault in the ventilation system, the PLC will print a warning message to the cryo control room printer and flash a descriptive warning on the ODH/ventilation graphics page. This fault is also logged to the Xpresslink graphics alarm page and to an alarm history hard disk file. The ventilation failure is also an input to the auto dialer which will continue it's automatic sequence until acknowledged. EF-6 delivers 13000 C.F.M. and is considered emergency ventilation. EF-7 delivers 4500 C.F.M. and will run 24 hrs a day. Both ventilation fans are located in an enclosed closet in the TRD gas room. Their ductwork, both inlets and outlets run along side the pipe chase, but are separated by an airtight wall. Their combination motor control starter cabinets are located in the TRD room in plain visible sight of the fans with the closet door open. The fans have signs that state they are automatically controlled and can energize at any time.

Signatures of Late Pleistocene fluvial incision in an Alpine landscape

Science.gov (United States)

Leith, Kerry; Fox, Matthew; Moore, Jeffrey R.

2018-02-01

Uncertainty regarding the relative efficacy of fluvial and glacial erosion has hindered attempts to quantitatively analyse the Pleistocene evolution of alpine landscapes. Here we show that the morphology of major tributaries of the Rhone River, Switzerland, is consistent with that predicted for a landscape shaped primarily by multiple phases of fluvial incision following a period of intense glacial erosion after the mid-Pleistocene transition (∼0.7 Ma). This is despite major ice sheets reoccupying the region during cold intervals since the mid-Pleistocene. We use high-resolution LiDAR data to identify a series of convex reaches within the long-profiles of 18 tributary channels. We propose these reaches represent knickpoints, which developed as regional uplift raised tributary bedrock channels above the local fluvial baselevel during glacial intervals, and migrated upstream as the fluvial system was re-established during interglacial periods. Using a combination of integral long-profile analysis and stream-power modelling, we find that the locations of ∼80% of knickpoints in our study region are consistent with that predicted for a fluvial origin, while the mean residual error over ∼100 km of modelled channels is just 26.3 m. Breaks in cross-valley profiles project toward the elevation of former end-of-interglacial channel elevations, supporting our model results. Calculated long-term uplift rates are within ∼15% of present-day measurements, while modelled rates of bedrock incision range from ∼1 mm/yr for low gradient reaches between knickpoints to ∼6-10 mm/yr close to retreating knickpoints, typical of observed rates in alpine settings. Together, our results reveal approximately 800 m of regional uplift, river incision, and hillslope erosion in the lower half of each tributary catchment since 0.7 Ma.

Development of regularized expectation maximization algorithms for fan-beam SPECT data

International Nuclear Information System (INIS)

Kim, Soo Mee; Lee, Jae Sung; Lee, Dong Soo; Lee, Soo Jin; Kim, Kyeong Min

2005-01-01

SPECT using a fan-beam collimator improves spatial resolution and sensitivity. For the reconstruction from fan-beam projections, it is necessary to implement direct fan-beam reconstruction methods without transforming the data into the parallel geometry. In this study, various fan-beam reconstruction algorithms were implemented and their performances were compared. The projector for fan-beam SPECT was implemented using a ray-tracing method. The direct reconstruction algorithms implemented for fan-beam projection data were FBP (filtered backprojection), EM (expectation maximization), OS-EM (ordered subsets EM) and MAP-EM OSL (maximum a posteriori EM using the one-step late method) with membrane and thin-plate models as priors. For comparison, the fan-beam projection data were also rebinned into the parallel data using various interpolation methods, such as the nearest neighbor, bilinear and bicubic interpolations, and reconstructed using the conventional EM algorithm for parallel data. Noiseless and noisy projection data from the digital Hoffman brain and Shepp/Logan phantoms were reconstructed using the above algorithms. The reconstructed images were compared in terms of a percent error metric. For the fan-beam data with Poisson noise, the MAP-EM OSL algorithm with the thin-plate prior showed the best result in both percent error and stability. Bilinear interpolation was the most effective method for rebinning from the fan-beam to parallel geometry when the accuracy and computation load were considered. Direct fan-beam EM reconstructions were more accurate than the standard EM reconstructions obtained from rebinned parallel data. Direct fan-beam reconstruction algorithms were implemented, which provided significantly improved reconstructions

Multi-objective optimization design and experimental investigation of centrifugal fan performance

Science.gov (United States)

Zhang, Lei; Wang, Songling; Hu, Chenxing; Zhang, Qian

2013-11-01

Current studies of fan performance optimization mainly focus on two aspects: one is to improve the blade profile, and another is only to consider the influence of single impeller structural parameter on fan performance. However, there are few studies on the comprehensive effect of the key parameters such as blade number, exit stagger angle of blade and the impeller outlet width on the fan performance. The G4-73 backward centrifugal fan widely used in power plants is selected as the research object. Based on orthogonal design and BP neural network, a model for predicting the centrifugal fan performance parameters is established, and the maximum relative errors of the total pressure and efficiency are 0.974% and 0.333%, respectively. Multi-objective optimization of total pressure and efficiency of the fan is conducted with genetic algorithm, and the optimum combination of impeller structural parameters is proposed. The optimized parameters of blade number, exit stagger angle of blade and the impeller outlet width are seperately 14, 43.9°, and 21 cm. The experiments on centrifugal fan performance and noise are conducted before and after the installation of the new impeller. The experimental results show that with the new impeller, the total pressure of fan increases significantly in total range of the flow rate, and the fan efficiency is improved when the relative flow is above 75%, also the high efficiency area is broadened. Additionally, in 65% -100% relative flow, the fan noise is reduced. Under the design operating condition, total pressure and efficiency of the fan are improved by 6.91% and 0.5%, respectively. This research sheds light on the considering of comprehensive effect of impeller structrual parameters on fan performance, and a new impeller can be designed to satisfy the engineering demand such as energy-saving, noise reduction or solving air pressure insufficiency for power plants.

The Female Vikings, a women's fan group in Denmark

DEFF Research Database (Denmark)

Mintert, Svenja-Maria; Pfister, Gertrud Ursula

2014-01-01

on the historical development of a Danish women-only fan group called 'The Female Vikings', which support a professional football club, Lyngby Boldklub (BK), in a city north of Copenhagen. The article explores the backgrounds and motivations of female fans, as well as their ways of staging femininity in a man...... of the female fans during the club's 'crisis' and their 'collective memories'....

Fifty shades of exploitation: Fan labor and Fifty Shades of Grey

Directory of Open Access Journals (Sweden)

Bethan Jones

2014-03-01

Full Text Available This exploration of the debates that have taken place in fandom over the ethics of pulling fan fiction and publishing it as original work draws on the notion of the fannish gift economy, which postulates that gifts such as fan fiction and fan art have value in the fannish community because they are designed to create and cement its social structure. Tension exists between fans who subscribe to the notion of a fannish gift economy and those who exploit fandom by using it to sell their pulled-to-publish works. An examination of E. L. James's 2012 Fifty Shades trilogy (comprising the books Fifty Shades of Grey, Fifty Shades Darker, and Fifty Shades Freed, which began as Twilight fan fiction, in addition to Twilight fan art sold through sites such as Redbubble and Etsy, demonstrates a tension between the two modes of fan expression: sale of artworks appears to be an acceptable practice in fandom, but the commercial sale of fan fic, even when marketed as original fiction, is widely contested.

Improving Fan System Performance: A Sourcebook for Industry

Energy Technology Data Exchange (ETDEWEB)

2003-04-01

This is one of a series of sourcebooks on motor-driven equipment produced by the Industrial Technologies Program. It provides a reference for industrial fan systems users, outlining opportunities to improve fan system performance.

High pressure axial flow fans for modern coal power stations

Energy Technology Data Exchange (ETDEWEB)

Cyrus, Vaclav [AHT Energetika s.r.o., Praha (Czech Republic); Koci, Petr [ZVVZ Milevsko a.s. (Czech Republic)

2008-07-01

Brown coal fired power stations, located in Northern Bohemia, have mostly older boiler blocks with an output of 110 and 200 MWe. Flue gases are cleaned by the desulphurization plants installed between 1993 and 1997. Usually, each boiler block has two air fans and one to three flue gas fans. Flue gas fans operate in severe conditions; fan blades should be resistant to the flue gases containing sulphur and acid drops with the operating temperature at 170 C to 190 C. Additionally, flue gas also often contains ash particles. Currently, some boiler blocks are gradually being refurbished. New blocks with an electrical power output of 600 to 700 MWe are at the design stage. Submitted paper shows our design study of one stage axial flow fan for the new blocks. Results from the new aerodynamic research of the axial flow stages were used in the fan design. (orig.)

Mean streamline analysis for performance prediction of cross-flow fans

International Nuclear Information System (INIS)

Kim, Jae Won; Oh, Hyoung Woo

2004-01-01

This paper presents the mean streamline analysis using the empirical loss correlations for performance prediction of cross-flow fans. Comparison of overall performance predictions with test data of a cross-flow fan system with a simplified vortex wall scroll casing and with the published experimental characteristics for a cross-flow fan has been carried out to demonstrate the accuracy of the proposed method. Predicted performance curves by the present mean streamline analysis agree well with experimental data for two different cross-flow fans over the normal operating conditions. The prediction method presented herein can be used efficiently as a tool for the preliminary design and performance analysis of general-purpose cross-flow fans

Genes2FANs: connecting genes through functional association networks

Science.gov (United States)

2012-01-01

Background Protein-protein, cell signaling, metabolic, and transcriptional interaction networks are useful for identifying connections between lists of experimentally identified genes/proteins. However, besides physical or co-expression interactions there are many ways in which pairs of genes, or their protein products, can be associated. By systematically incorporating knowledge on shared properties of genes from diverse sources to build functional association networks (FANs), researchers may be able to identify additional functional interactions between groups of genes that are not readily apparent. Results Genes2FANs is a web based tool and a database that utilizes 14 carefully constructed FANs and a large-scale protein-protein interaction (PPI) network to build subnetworks that connect lists of human and mouse genes. The FANs are created from mammalian gene set libraries where mouse genes are converted to their human orthologs. The tool takes as input a list of human or mouse Entrez gene symbols to produce a subnetwork and a ranked list of intermediate genes that are used to connect the query input list. In addition, users can enter any PubMed search term and then the system automatically converts the returned results to gene lists using GeneRIF. This gene list is then used as input to generate a subnetwork from the user’s PubMed query. As a case study, we applied Genes2FANs to connect disease genes from 90 well-studied disorders. We find an inverse correlation between the counts of links connecting disease genes through PPI and links connecting diseases genes through FANs, separating diseases into two categories. Conclusions Genes2FANs is a useful tool for interpreting the relationships between gene/protein lists in the context of their various functions and networks. Combining functional association interactions with physical PPIs can be useful for revealing new biology and help form hypotheses for further experimentation. Our finding that disease genes in

Should electric fans be used during a heat wave?

Science.gov (United States)

Jay, Ollie; Cramer, Matthew N; Ravanelli, Nicholas M; Hodder, Simon G

2015-01-01

Heat waves continue to claim lives, with the elderly and poor at greatest risk. A simple and cost-effective intervention is an electric fan, but public health agencies warn against their use despite no evidence refuting their efficacy in heat waves. A conceptual human heat balance model can be used to estimate the evaporative requirement for heat balance, the potential for evaporative heat loss from the skin, and the predicted sweat rate, with and without an electrical fan during heat wave conditions. Using criteria defined by the literature, it is clear that fans increase the predicted critical environmental limits for both the physiological compensation of endogenous/exogenous heat, and the onset of cardiovascular strain by an air temperature of ∼3-4 °C, irrespective of relative humidity (RH) for the young and elderly. Even above these critical limits, fans would apparently still provide marginal benefits at air temperatures as high as 51.1 °C at 10%RH for young adults and 48.1 °C at 10%RH for the elderly. Previous concerns that dehydration would be exacerbated with fan use do not seem likely, except under very hot (>40 °C) and dry (fans by a minor amount (∼20-30 mL/h). Relative to the peak outdoor environmental conditions reported during ten of the most severe heat waves in recent history, fan use would be advisable in all of these situations, even when reducing the predicted maximum sweat output for the elderly. The protective benefit of fans appears to be underestimated by current guidelines. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Fluvial organic carbon losses from oil palm plantations on tropical peat, Sarawak, Southeast Asia

Science.gov (United States)

Cook, Sarah; Page, Susan; Evans, Chris; Whelan, Mick; Gauci, Vincent; Lip Khoon, Kho

2017-04-01

peatland carbon budget. Given the increasing expansion of oil palm plantations on tropical peat, within Southeast Asia, it is essential that fluvial organic carbon data is incorporated into assessment criteria, helping countries to better monitor, report and verify their land-based greenhouse gas emissions.

Fluvial-deltaic sedimentation and stratigraphy of the ferron sandstone

Science.gov (United States)

Anderson, P.B.; Chidsey, T.C.; Ryer, T.A.

1997-01-01

East-central Utah has world-class outcrops of dominantly fluvial-deltaic Turonian to Coniacian aged strata deposited in the Cretaceous foreland basin. The Ferron Sandstone Member of the Mancos Shale records the influences of both tidal and wave energy on fluvial-dominated deltas on the western margin of the Cretaceous western interior seaway. Revisions of the stratigraphy are proposed for the Ferron Sandstone. Facies representing a variety of environments of deposition are well exposed, including delta-front, strandline, marginal marine, and coastal-plain. Some of these facies are described in detail for use in petroleum reservoir characterization and include permeability structure.

Two studies on the effects of small exhaust fans on indoor air quality: Field study of exhaust fans for mitigating indoor air quality problems; Indoor air quality, exhaust fan mitigation

International Nuclear Information System (INIS)

1987-07-01

Overall, the findings show that exhaust fans basically provide small amounts of ventilation compensation. By monitoring the common indoor air pollutants (radon, formaldehyde, carbon monoxide, nitrogen dioxide, and water vapor), it was found that the quality of the indoor air was not adversely affected by the use of exhaust fans. Nor did their use provide any measurable or significant benefits since no improvement in air quality was ascertained. While exhaust fans of this small size did not increase radon, which is the contaminant of most concern, the researchers caution that operation of a larger fan or installation in a very tight home could result in higher levels because depressurization is greater. The daily energy consumption for use of these appliances during the heating season was calculated to be 1.5 kilowatt hours or approximately 3% of the energy consumption in the study homes. The information collected in this collaborative field study indicates that the use of these particular ventilation systems has no significant effect on indoor air quality

Sediment dynamics in the Rhine catchment : Quantification of fluvial response to climate change and human impact

NARCIS (Netherlands)

Erkens, G.

2009-01-01

Fluvial systems are strongly responsive to changes in climate and land use — but take their time to show it. Accurate prediction of the timing and degree of future fluvial response requires comprehensive understanding of fluvial response in the past. This PhD-thesis studied the response of the river

Assessment of indoor air quality in comparison using air conditioning and fan system in printing premise

Directory of Open Access Journals (Sweden)

Ramlan Nazirah

2017-01-01

Full Text Available Printers contribute to various emissions consist with chemical contaminants. High concentration of the particulate matter can cause serious health problems. This study focuses on the indoor air quality in printing premise unit in Universiti Tun Hussein Onn, Malaysia. Field testing involving air sampling methods were taken from 900 hours to 1600 hours, for every 30 minutes using physical measurement which is Multi-Channel Air Quality Monitor (YESAIR, E-Sampler and Ozone Meter. Air sampling was recorded based on one sampling point and most suitable point for production. A comparison based on different ventilation using fan and air-conditioning were also taken and results is being compared based on OSHA and NIOSH standards. Besides that, the statistical analysis is being conducted in order to predict the effect on number of printers. From the result, the O3 concentrations show, 10% reduced for printing premise using fan ventilation compared to air-conditioning but remain the same value for PM2.5. The concentration of O3 increased when the number of printers decreased, while the concentration of PM2.5 increased the increase of printers number. Overall, the use of fan in printing premise is more suggested since the level is slightly lower than the printing premise using air-conditioning.

Dead links, vaporcuts, and creativity in fan edit replication

Directory of Open Access Journals (Sweden)

Joshua Wille

2015-09-01

Full Text Available In my examination of a Star Wars prequel trilogy fan edit reportedly made by Topher Grace, I introduce the term vaporcut to describe fan edits with reputations that may generate critical discourse but that are not publicly released. I explore the ways some fan editors attempt to recreate intangible projects but inevitably produce variant works that reflect their own creative perspectives.

SWITCHING POWER FAN CONTROL OF COMPUTER

Directory of Open Access Journals (Sweden)

Oleksandr I. Popovskyi

2010-10-01

Full Text Available Relevance of material presented in the article, due to extensive use of high-performance computers to create modern information systems, including the NAPS of Ukraine. Most computers in NAPS of Ukraine work on Intel Pentium processors at speeds from 600 MHz to 3 GHz and release a lot of heat, which requires the installation of the system unit 2-3 additional fans. The fan is always works on full power, that leads to rapid deterioration and high level (up to 50 dB noise. In order to meet ergonomic requirements it is proposed to іnstall a computer system unit and an additional control unit ventilators, allowing independent control of each fan. The solution is applied at creation of information systems planning research in the National Academy of Pedagogical Sciences of Ukraine on Internet basis.

Noise Measurements of the VAIIPR Fan

Science.gov (United States)

Mendoza, Jeff; Weir, Don

2012-01-01

This final report has been prepared by Honeywell Aerospace, Phoenix, Arizona, a unit of Honeywell International, Inc., documenting work performed during the period September 2004 through November 2005 for the National Aeronautics and Space Administration (NASA) Glenn Research Center, Cleveland, Ohio, under the Revolutionary Aero-Space Engine Research (RASER) Program, Contract No. NAS3- 01136, Task Order 6, Noise Measurements of the VAIIPR Fan. The NASA Task Manager was Dr. Joe Grady, NASA Glenn Research Center, Mail Code 60-6, Cleveland, Ohio 44135. The NASA Contract Officer was Mr. Albert Spence, NASA Glenn Research Center, Mail Code 60-6, Cleveland, Ohio 44135. This report focuses on the evaluation of internal fan noise as generated from various inflow disturbances based on measurements made from a circumferential array of sensors located near the fan and sensors upstream of a serpentine inlet.

Fans of Columbine shooters Eric Harris and Dylan Klebold

Directory of Open Access Journals (Sweden)

Andrew Ryan Rico

2015-09-01

Full Text Available On April 20, 1999, Eric Harris and Dylan Klebold murdered 12 students and one teacher at Columbine High School in Littleton, Colorado, in what was then the deadliest school shooting in American history. Despite causing a national panic and serving as a flash point for larger narratives on bullying, gun control, and media violence, both boys have gained active online fans. These fandoms dedicated to the Columbine shooters are widely referred to as dark examples of Internet communities, while the fans are also frequently denigrated as unstable and violent outcasts. Such dark online fandoms are yet to permeate mainstream culture or to challenge the preexisting perception of these communities as breeding grounds for the next wave of school shooters. While studies have covered the types of fans and their myriad interests, the field remains focused on more conventional examples of fan communities. In an effort to challenge and expand the object of focus when we study fandom, this qualitative study examines Columbine fans and their activity in order to understand the dominant motives they appear to have for engaging with and around such controversial figures and then concludes by exploring how this community might help us reflect more broadly on our concept of fandom. Redeeming these fans as part of diverse and complex communities of social relevance can demonstrate how even a dark fandom such as that of these Columbine shooters provides valuable cultural insights and benefits the field of fan studies.

The benefits of conducting factory performance tests for main mine fans

Energy Technology Data Exchange (ETDEWEB)

Ray, R.E.Jr. [PB Americas Inc., New York, NY (United States); Gamble, G.A. [Clarage Twin City Fan Co., Akron, OH (United States)

2010-07-01

Axial flow fans used in underground mining are also commonly used in subway tunnel ventilation fans to provide an evacuation path during a tunnel fire emergency. The axial flow fans provide sufficient air velocity to the fire site to prevent backlayering of smoke against the incoming airflow. Since the tunnels are used by the public, advance testing of fans and motors is conducted to confirm that the equipment will perform as specified during a fire. This paper discussed some of the advantages derived from conducting fan factory tests for tunnel projects that would also apply to mining applications. It also described other benefits from testing that are unique to mining. External factors that may cause the fan performance to vary considerably from the predicted performance measured at the factory were also discussed. These included air density changes and system effects produced by poorly designed shaft configurations and fan inlet ductwork. 11 refs., 6 figs.

Flow performance of highly loaded axial fan with bowed rotor blades

Science.gov (United States)

Chen, L.; Liu, X. J.; Yang, A. L.; Dai, R.

2013-12-01

In this paper, a partial bowed rotor blade was proposed for a newly designed high loaded axial fan. The blade was positively bowed 30 degrees from hub to 30 percent spanwise position. Flows of radial blade and bowed blade fans were numerically compared for various operation conditions. Results show that the fan's performance is improved. At the designed condition with flow coefficient of 0.52, the efficiency of the bowed blade fan is increased 1.44% and the static pressure rise is increased 11%. Comparing the flow structures, it can be found that the separated flow in the bowed fan is reduced and confined within 20 percent span, which is less than the 35 percent in the radial fan. It means that the bowed blade generates negative blade force and counteracts partial centrifugal force. It is alleviates the radial movements of boundary layers in fan's hub region. Flow losses due to 3D mixing are reduced in the rotor. Inlet flow to downstream stator is also improved.

Design definition study of a life/cruise fan technology V/STOL aircraft. Volume 2, addendum 2: Program risk assessment

Science.gov (United States)

1975-01-01

The results are presented of a risk assessment study conducted on two technology aircraft. The aircraft system components were reviewed and assessed for risk based on: (1) complexity relative to state-of-the-art, (2) manufacturing and qualification testing, (3) availability and delays, and (4) cost/schedule impact. These assessments were based on five risk nomenclatures: low, minor, moderate, high, and extreme. Each aircraft system was assigned an overall risk rating depending upon its contribution to the capability of the aircraft to achieve the performance goals. The slightly lower Sabreliner performance margin is due to the restricted flight envelope, the fixed landing gear, and internal fuel capacity. The Sabreliner with retractable gear and allowed to fly at its best speed and altitude would reflect performance margins similar to the New Airframe. These significant margins, inherent with the MCAIR three gas generator/three fan propulsion system, are major modifiers to risk assessment of both aircraft. The estimated risk and the associated key system and performance areas are tabulated.

30 CFR 57.4131 - Surface fan installations and mine openings.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Surface fan installations and mine openings. 57... Fire Prevention and Control Prohibitions/precautions/housekeeping § 57.4131 Surface fan installations... stored within 100 feet of mine openings or within 100 feet of fan installations used for underground...

30 CFR 57.22203 - Main fan operation (I-C mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main fan operation (I-C mines). 57.22203... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22203 Main fan operation (I-C mines). Main fans shall be operated continuously while ore production is in progress. ...

Performance Testing Of A Modified Centrifugal Fan With Serrated Blade Impeller

Directory of Open Access Journals (Sweden)

Zaimar

2017-10-01

Full Text Available Changes of shape dimension and component part of impeller might change of characteristic fluid flow so that pressure static in the fan housing changed. Changing some geometric characteristics of the centrifugal fan has more efficiency taking with energy crises into consideration. Several factors that can affect fan performance namely design and type size rotation speed air condition or gas through a fan operating point on the nature of the relationship between a volume of air flow and pressure. The purpose of this research was to test of fan performance of the modified centrifugal fan with the serrated blade impeller. The addition of a percentage of closing the inlet causes the air volumetric rate the airflow energy BHP and total efficiency except for the fan total and static pressure. The experimental test results there are static pressure data and the resulting total pressure is different or distorted 10-17 of deviation from calculation data based on the fan laws. This is possible because of changes in the shape of the blade with serrated on the inside of the impeller. Based on the performance curve shows that the selection of impeller speeds of 800 RPM produces a relatively high air volumetric rate is proportional to the total pressure of the fan and the flow energy so that it is more efficient than other impeller speeds.

Gender constructions and negotiations of female football fans

DEFF Research Database (Denmark)

Lenneis, Verena; Pfister, Gertrud Ursula

2015-01-01

While both the media and the academic literature focus primarily on male fans, in particular on violence and the prevention of hooliganism, little is known about female football supporters. This is also true of Denmark, a country that is known for its high degree of gender equality. This article...... aims to give insight into gender constructions and negotiations of female football fans in the stands. Drawing on a social constructivist perspective to gender and Bourdieu's (1984) approaches to field, capital and habitus, we explored the experiences and opinions of female fans. The methods employed...

GOEMORFOLOGIA FLUVIAL DA BACIA HIDROGRÁFICA DO RIO DE ONDAS

Directory of Open Access Journals (Sweden)

Ossifleres Silva Damasceno

2011-10-01

Full Text Available Os estudos de Geomorfologia Fluvial para analise de Bacias Hidrográficas vêm tendo nos últimos tempos grande importância, tanto para se conhecer as características de determinadas bacias como para se planejar o uso de tais recursos. Neste sentido, este trabalho foi efetuado no intuito de somar aos estudos anteriormente executados nessa bacia, levantando algumas características geomorfológicas, o uso e ocupação atual. Palavras-chaves: geomorfologia fluvial, hidrografia, agricultura irrigada.

Portable Life Support System 2.5 Fan Design and Development

Science.gov (United States)

Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

2016-01-01

NASA is building a high-fidelity prototype of an advanced Portable Life Support System (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, was driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement were identified with the PLSS 2.0 fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0, and it uses the same nonmetallic, canned motor, with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 ventilation loop. The larger impeller allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds consistent with prior, oxygen-rated fans. Development of the fan also considered a shrouded impeller design that could allow larger clearances for greater oxygen safety, assembly tolerances and particle ingestion. This paper discusses the design, manufacturing and performance testing of the new fans.

Surficial geological tools in fluvial geomorphology: Chapter 2

Science.gov (United States)

Jacobson, Robert B.; O'Connor, James E.; Oguchi, Takashi

2016-01-01

Increasingly, environmental scientists are being asked to develop an understanding of how rivers and streams have been altered by environmental stresses, whether rivers are subject to physical or chemical hazards, how they can be restored, and how they will respond to future environmental change. These questions present substantive challenges to the discipline of fluvial geomorphology, especially since decades of geomorphologic research have demonstrated the general complexity of fluvial systems. It follows from the concept of complex response that synoptic and short-term historical views of rivers will often give misleading understanding of future behavior. Nevertheless, broadly trained geomorphologists can address questions involving complex natural systems by drawing from a tool box that commonly includes the principles and methods of geology, hydrology, hydraulics, engineering, and ecology.

The Role of Flow Diagnostic Techniques in Fan and Open Rotor Noise Modeling

Science.gov (United States)

Envia, Edmane

2016-01-01

A principal source of turbomachinery noise is the interaction of the rotating and stationary blade rows with the perturbations in the airstream through the engine. As such, a lot of research has been devoted to the study of the turbomachinery noise generation mechanisms. This is particularly true of fan and open rotors, both of which are the major contributors to the overall noise output of modern aircraft engines. Much of the research in fan and open rotor noise has been focused on developing theoretical models for predicting their noise characteristics. These models, which run the gamut from the semi-empirical to fully computational ones, are, in one form or another, informed by the description of the unsteady flow-field in which the propulsors (i.e., the fan and open rotors) operate. Not surprisingly, the fidelity of the theoretical models is dependent, to a large extent, on capturing the nuances of the unsteady flowfield that have a direct role in the noise generation process. As such, flow diagnostic techniques have proven to be indispensible in identifying the shortcoming of theoretical models and in helping to improve them. This presentation will provide a few examples of the role of flow diagnostic techniques in assessing the fidelity and robustness of the fan and open rotor noise prediction models.

Recent progress in fan and compressor for aeroengine. Koku engine yo fan asshukuki no saikin no gijutsu shinpo

Energy Technology Data Exchange (ETDEWEB)

Saito, Y [National Aerospace Lab., Chofu, Tokyo (Japan)

1994-03-10

As the main components of the aeroengine, the fan and compressor reach to extremely high level stage technologically. Also at present when about 50 years passed after the jet engine was applied in practice, however, an effort for a modification is being continued, and furthermore even in the 1990s, the engines that adopted the new technologies are in succession being put in practical application. New engines in the 1990s are being applied in practice by adopting the study results on fan and compressor from the 1970s to the 1980s. Because, which way the future fan and compressor of the aircraft will go to has a relation with an aircraft trend from now on, and even in the 2000s the high subsonic speed aircrafts will be a center of the private air planes. The engine of high subsonic speed aircraft in the next generation will become an ultrahigh bypass ratio engine, the thrust efficiency is raised and noise is lowered, by lowering a fan pressure ratio and by increasing an air flow quantity compared with the current high bypass ratio turbofan engine. 16 figs.

On-chip grating coupler array on the SOI platform for fan-in/fan-out of multi-core fibers with low insertion loss and crosstalk

DEFF Research Database (Denmark)

Ding, Yunhong; Ye, Feihong; Peucheret, Christophe

2014-01-01

We design and fabricate a compact multi-core fiber fan-in/fan-out using a fully-etched grating coupler array on the SOI platform. Lowest coupling loss of 6.8 dB with 3 dB bandwidth of 48 nm and crosstalk lower than ×32 dB are demonstrated.......We design and fabricate a compact multi-core fiber fan-in/fan-out using a fully-etched grating coupler array on the SOI platform. Lowest coupling loss of 6.8 dB with 3 dB bandwidth of 48 nm and crosstalk lower than ×32 dB are demonstrated....

Fluvial system response to Late Devensian (Weichselian) aridity, Baston, Lincolnshire, England

Science.gov (United States)

Briant, Rebecca M.; Coope, G. Russell; Preece, Richard C.; Keen, David H.; Boreham, Steve; Griffiths, Huw I.; Seddon, Mary B.; Gibbard, Philip L.

2004-07-01

Little is known about the impact of Late Devensian (Weichselian) aridity on lowland British landscapes, largely because they lack the widespread coversand deposits of the adjacent continent. The concentration of large interformational ice-wedge casts in the upper part of many Devensian fluvial sequences suggests that fluvial activity may have decreased considerably during this time. The development of optically stimulated luminescence (OSL) dating enables this period of ice-wedge cast formation to be constrained for the first time in eastern England, where a marked horizon of ice-wedge casts is found between two distinctive dateable facies associations. Contrasts between this horizon and adjacent sediments show clear changes in environment and fluvial system behaviour in response to changing water supply, in line with palaeontological evidence. In addition to providing chronological control on the period of ice-wedge formation, the study shows good agreement of the radiocarbon and OSL dating techniques during the Middle and Late Devensian, with direct comparison of these techniques beyond 15 000 yr for the first time in Britain. It is suggested that aridity during the Late Devensian forced a significant decrease in fluvial activity compared with preceding and following periods, initiating a system with low peak flows and widespread permafrost development. Copyright

Lacustrine-fluvial interactions in Australia's Riverine Plains

Science.gov (United States)

Kemp, Justine; Pietsch, Timothy; Gontz, Allen; Olley, Jon

2017-06-01

Climatic forcing of fluvial systems has been a pre-occupation of geomorphological studies in Australia since the 1940s. In the Riverine Plain, southeastern Australia, the stable tectonic setting and absence of glaciation have combined to produce sediment loads that are amongst the lowest in the world. Surficial sediments and landforms exceed 140,000 yr in age, and geomorphological change recorded in the fluvial, fluvio-lacustrine and aeolian features have provided a well-studied record of Quaternary environmental change over the last glacial cycle. The region includes the Willandra Lakes, whose distinctive lunette lakes preserve a history of water-level variations and ecological change that is the cornerstone of Australian Quaternary chronostratigraphy. The lunette sediments also contain an ancient record of human occupation that includes the earliest human fossils yet found on the Australian continent. To date, the lake-level and palaeochannel records in the Lachlan-Willandra system have not been fully integrated, making it difficult to establish the regional significance of hydrological change. Here, we compare the Willandra Lakes environmental record with the morphology and location of fluvial systems in the lower Lachlan. An ancient channel belt of the Lachlan, Willandra Creek, acted as the main feeder channel to Willandra Lakes before channel avulsion caused the lakes to dry out in the late Pleistocene. Electromagnetic surveys, geomorphological and sedimentary evidence are used to reconstruct the evolution of the first new channel belt following the avulsion. Single grain optical dating of floodplain sediments indicates that sedimentation in the new Middle Billabong Palaeochannel had commenced before 18.4 ± 1.1 ka. A second avulsion shifted its upper reaches to the location of the present Lachlan River by 16.2 ± 0.9 ka. The timing of these events is consistent with palaeohydrological records reconstructed from Willandra Lakes and with the record of

Upper Pleistocene turbidite sand beds and chaotic silt beds in the channelized, distal, outer-fan lobes of the Mississippi fan

Science.gov (United States)

Nelson, C.H.; Twichell, D.C.; Schwab, W.C.; Lee, H.J.; Kenyon, Neil H.

1992-01-01

Cores from a Mississippi outer-fan depositional lobe demonstrate that sublobes at the distal edge contain a complex local network of channelized-turbidite beds of graded sand and debris-flow beds of chaotic silt. Off-lobe basin plains lack siliciclastic coarse-grained beds. The basin-plain mud facies exhibit low acoustic backscatter on SeaMARC IA sidescan sonar images, whereas high acoustic backscatter characteristic of the lobe sand and silt facies. The depth of the first sand-silt layer correlates with relative backscatter intensity and stratigraphic age of the distal sublobes (i.e., shallowest sand = highest backscatter and youngest sublobe). The high proportion (>50%) of chaotic silt compared to graded sand in the distal, outer-fan sublobes may be related to the unstable, muddy, canyon-wall source areas of the extensive Mississippi delta-fed basin slope. A predominace of chaotic silt in cores or outcrops from outer-fan lobes thus may predict similar settings for ancient fans.

Reactive control of subsonic axial fan noise in a duct.

Science.gov (United States)

Liu, Y; Choy, Y S; Huang, L; Cheng, L

2014-10-01

Suppressing the ducted fan noise at low frequencies without varying the flow capacity is still a technical challenge. This study examines a conceived device consisting of two tensioned membranes backed with cavities housing the axial fan for suppression of the sound radiation from the axial fan directly. The noise suppression is achieved by destructive interference between the sound fields from the axial fan of a dipole nature and sound radiation from the membrane via vibroacoustics coupling. A two-dimensional model with the flow effect is presented which allows the performance of the device to be explored analytically. The air flow influences the symmetrical behavior and excites the odd in vacuo mode response of the membrane due to kinematic coupling. Such an asymmetrical effect can be compromised with off-center alignment of the axial fan. Tension plays an important role to sustain the performance to revoke the deformation of the membrane during the axial fan operation. With the design of four appropriately tensioned membranes covered by a cylindrical cavity, the first and second blade passage frequencies of the axial fan can be reduced by at least 20 dB. The satisfactory agreement between experiment and theory demonstrates that its feasibility is practical.

Human and natural impacts on fluvial and karst depressions of the Maya Lowlands

Science.gov (United States)

Beach, Timothy; Luzzadder-Beach, Sheryl; Dunning, Nicholas; Cook, Duncan

2008-10-01

This paper begins to differentiate the major drivers and chronology of erosion and aggradation in the fluvial and fluviokarst landscapes of the southern and central Maya Lowlands. We synthesize past research on erosion and aggradation and add new data from water, soils, radiocarbon dating, and archaeology to study the quantity, timing, and causes of aggradation in regional landscape depressions. Geomorphic findings come from many excavations across a landscape gradient from upland valleys, karst sinks, and fans into the coastal plain floodplains and depressions. Findings from water chemistry show that sources in the uplands have low quantities of dissolved ions but water in the coastal plains has high amounts of dissolved ions, often nearly saturated in calcium and sulfate. We found significant geomorphic complexity in the general trends in upland karst sinks. In a few instances, sediments preserve Late Pleistocene paleosols, buried 2-3 m, though many more have distinct middle to late Holocene paleosols, buried 1-2 m, after c. 2300 BP (Maya Early to Late Preclassic). From 2300-1100 BP (Late Preclassic to Classic Periods), the landscape aggraded from five main mechanisms: river flooding, climatic instability, accelerated erosion, ancient Maya landscape manipulation, and gypsum precipitation from a rise in a water table nearly saturated in calcium and sulfate ions. Evidence exists for two or three high magnitude floods, possibly driven by hurricanes. Moreover, lake-core and geophysical studies from the Petén Lakes region have shown high rates of deposition of silicate clays ('Maya Clays') starting and peaking during the Maya Preclassic and continuing to be high through the Late Classic. The main driver on upland karst depressions, the Petén lakes, upland valleys, and fans was accelerated soil erosion, but water table rise, probably driven by sea-level rise, was the main driver on the wetlands of the coastal plain because the aggraded sediments here are dominantly

30 CFR 75.312 - Main mine fan examinations and records.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fan examinations and records. 75.312... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.312 Main mine fan examinations and records. (a) To assure electrical and mechanical reliability of main mine fans, each main mine...

Representation of American versus non-American fans in Baillie Walsh's Springsteen & I

NARCIS (Netherlands)

Wilkinson, M.C.

2015-01-01

This article explores the representation of American versus non-American fans in Baillie Walsh's 2013 crowd/fan-sourced documentary Springsteen & I. The film—as much as it was fed by a wide and international range of fan-produced material—ultimately produced and presented one particular type of fan

Sports Fans, Alcohol Use, and Violent Behavior: A Sociological Review.

Science.gov (United States)

Ostrowsky, Michael K

2016-08-31

This review makes four contributions to the sociological study of sports fans, alcohol use, and violent behavior. First, this article focuses explicitly on the relationship between alcohol use and violent behavior among sports fans. This is a worldwide social problem, yet it is quite understudied. Second, this article synthesizes the fragmented literature on alcohol use and violent behavior among sports fans. Third, this article identifies four broad sets of risk factors-sociocultural, event/venue, police, and crowd-that appear to be closely related to violent behavior among sports fans. Finally, to help explain the possible correlation between alcohol and violence among sports fans, this article draws upon the key understandings from the literature on alcohol and violence in wider society. The article concludes with suggestions for future research. © The Author(s) 2016.

The Gediz River fluvial archive : A benchmark for Quaternary research in Western Anatolia

NARCIS (Netherlands)

Maddy, D.; Veldkamp, A.; Demir, T.; van Gorp, W.; Wijbrans, J.R.; van Hinsbergen, D.J.J.; Dekkers, M.J.; Schreve, D.; Schoorl, J.M.; Scaife, R.; Stemerdink, C.; van der Schriek, T.; Bridgland, D.R.; Aytaç, A.S.

2017-01-01

The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River

Influence of wind velocity fluctuation on air temperature difference between the fan and ground levels and the effect of frost protective fan operation

International Nuclear Information System (INIS)

Araki, T.; Matsuo, K.; Miyama, D.; Sumikawa, O.; Araki, S.

2008-01-01

We invested the influence of wind velocity fluctuation on air temperature difference between the fan (4.8 m) and ground levels (0.5 m) and the effect of frost protective fan operation in order to develop a new method to reduce electricity consumption due to frost protective fan operation. The results of the investigations are summarized as follows: (1) Air temperature difference between the fan (4.8 m) and ground levels (0.5 m) was decreased following an increase in wind velocity, and the difference was less than 1°C for a wind velocity more than 3.0 m/s at a height of 6.5 m. (2) When the wind velocity was more than 2-3 m/s, there was hardly any increase in the temperature of the leaves. In contrast, when the wind velocity was less than 2-3 m/s, an increase in the temperature of the leaves was observed. Based on these results, it is possible that when the wind velocity is greater than 2-3 m, it prevents thermal inversion. Therefore, there would be no warmer air for the frost protective fan to return to the tea plants and the air turbulence produced by the frost protective fan would not reach the plants under the windy condition

"The florals": Female fans over 50 in the Sherlock fandom

Directory of Open Access Journals (Sweden)

Line Nybro Petersen

2017-03-01

Full Text Available This article uses e-mail interviews with nine female fans to explore what it means to be a fan over the age of 50 of the popular BBC drama Sherlock (2010–. The research aims to better understand the role of fandom in later life, in particular how the participants in this study negotiate their perceptions of their subjective age in relation to being a fan in this part of their life course. This study combines theory on cultural gerontology with fan studies and mediatization theory in order to understand the dynamics and processes that guide fans' negotiations of subjective age as well as the role of fan practices and the affordances of social media in these processes. I argue that fandom, as a manifestation of a mediatized culture, augments the relevance of subjective age and informs the way in which participants in middle and later life perceive and negotiate their own subjective age specifically in relation to fandom as youth culture, women's passion, and creativity.

The underground main fan study at the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

McDaniel, K.H.; Chmura, K.M.

1996-01-01

The Waste Isolation Pilot Plant (WIPP) performed a feasibility analysis for the purpose of either modifying, supplementing, or replacing its two main mine fans. The WIPP, located near Carlsbad, New Mexico, is a US Department of Energy (DOE) facility designed to demonstrate the permanent, safe disposal of US defense-generated transuranic waste in a deep bedded salt deposit. Since the centrifugal fans were installed in 1988, multiple operational and performance concerns have been identified. A comprehensive engineering study was conducted in 1995 to: (1) qualify and quantify operational concerns; (2) evaluate possible alternatives; and (3) recommend an optimum solution. Multiple system modification and/or replacement scenarios were evaluated with associated cost estimates developed. The study considered replacement with either centrifugal or axial fans. Multiple fan duties are required at the WIPP. Therefore, Variable Frequency Drives and Inlet Vane Controls (IVC) were investigated for centrifugal fans. In-flight adjustable blades were investigated for axial fans. The study indicated that replacing the existing system with two double-width, double-inlet centrifugal fans equipped with IVCs was the best choice. This alternative provided the most desirable combination of: (1) ensuring the required operational readiness, and (2) improving system performance. The WIPP is currently planning to replace the first fan in 1997

Flow performance of highly loaded axial fan with bowed rotor blades

International Nuclear Information System (INIS)

Chen, L; Liu, X J; Yang, A L; Dai, R

2013-01-01

In this paper, a partial bowed rotor blade was proposed for a newly designed high loaded axial fan. The blade was positively bowed 30 degrees from hub to 30 percent spanwise position. Flows of radial blade and bowed blade fans were numerically compared for various operation conditions. Results show that the fan's performance is improved. At the designed condition with flow coefficient of 0.52, the efficiency of the bowed blade fan is increased 1.44% and the static pressure rise is increased 11%. Comparing the flow structures, it can be found that the separated flow in the bowed fan is reduced and confined within 20 percent span, which is less than the 35 percent in the radial fan. It means that the bowed blade generates negative blade force and counteracts partial centrifugal force. It is alleviates the radial movements of boundary layers in fan's hub region. Flow losses due to 3D mixing are reduced in the rotor. Inlet flow to downstream stator is also improved

Morphology and sedimentology of glacigenic submarine fans on the west Greenland continental margin

Science.gov (United States)

O'Cofaigh, Colm; Hogan, Kelly A.; Dowdeswell, Julian A.; Jennings, Anne E.; Noormets, Riko; Evans, Jeffrey

2014-05-01

Along the West Greenland continental margin adjoining Baffin Bay, bathymetric data show a series of large submarine fans located at the mouths of cross-shelf troughs. Two of these fans, the Uummannaq Fan and the Disko Fan are trough-mouth fans built largely of debris delivered from ice sheet outlets of the Greenland Ice Sheet during past glacial maxima. On the Uummannaq Fan glacigenic debris flow deposits occur on the upper slope and extend to at least 1800 m water depth in front of the trough-mouth. The debris flow deposits are related to the remobilisation of subglacial debris that was delivered onto the upper slope at times when an ice stream was positioned at the shelf edge. In contrast, sedimentary facies from the northern sector of the fan are characterised by hemipelagic and ice-rafted sediments and turbidites; glacigenic debris flows are notably absent in cores from this region. Further south along the Greenland continental margin the surface of the Disko Fan is prominently channelised and associated sediments are acoustically stratified. Although glacigenic debris flow deposits do occur on the upper Disko Fan, sediments recovered in cores from elsewhere on the fan record the influence of turbidity current and meltwater sedimentation. The channelised form of the Disko fan contrasts markedly with that of the Uummannaq Fan and, more widely, with trough mouth fans from the Polar North Atlantic. Collectively these data highlight the variability of glacimarine depositional processes operating on trough-mouth fans on high-latitude continental slopes and show that glacigenic debris flows are but one of a number of mechanisms by which such large glacially-influenced depocentres form.

Evidence of anthropogenic tipping points in fluvial dynamics in Europe

Science.gov (United States)

Notebaert, Bastiaan; Broothaerts, Nils; Verstraeten, Gert

2018-05-01

In this study the occurrence of thresholds in fluvial style changes during the Holocene are discussed for three different catchments: the Dijle and Amblève catchments (Belgium) and the Valdaine Region (France). We consider tipping points to be a specific type of threshold, defined as relatively rapid and irreversible changes in the system. Field data demonstrate that fluvial style has varied in all three catchments over time, and that different tipping points can be identified. An increase in sediment load as a result of human induced soil erosion lead to a permanent change in the Dijle floodplains from a forested peaty marsh towards open landscape with clastic deposition and a well-defined river channel. In the Valdaine catchment, an increase in coarse sediment load, caused by increased erosion in the mountainous upper catchment, altered the floodplains from a meandering pattern to a braided pattern. Other changes in fluvial style appeared to be reversible. Rivers in the Valdaine were prone to different aggradation and incision phases due to changes in peak water discharge and sediment delivery, but the impact was too low for these changes to be irreversible. Likewise the Dijle River has recently be prone to an incision phase due to a clear water effect, and also this change is expected to be reversible. Finally, the Amblève River did not undergo major changes in style during the last 2000 to 5000 years, even though floodplain sedimentation rates increased tenfold during the last 600 years. Overall, these examples demonstrate how changes in fluvial style depend on the crossing of thresholds in sediment supply and water discharge. Although changes in these controlling parameters are caused by anthropogenic land use changes, the link between those land use changes and changes in fluvial style is not linear. This is due to the temporal variability in landscape connectivity and sediment transport and the non-linear relationship between land use intensity and soil

Multiple view fan beam polarimetry on Tokamak devices

International Nuclear Information System (INIS)

Geck, W.R.; Domier, C.W.; Luhmann, N.C.

1997-01-01

A polarimeter diagnostic is under development which utilizes several fan beams to accumulate line integrated Faraday rotation data in a Tokamak plasma. The utilization of a fan beam configuration over that of conventional vertical view polarimeter systems significantly reduces access requirements. The high angular separation inherent in a fan beam implementation increases plasma coverage and eliminates the necessity of assumed plasma symmetries to generate high quality current density profiles. Codes have been developed to generate these high-resolution two-dimensional images of the plasma current profile from data collected at arbitrary positions and viewing angles. copyright 1997 American Institute of Physics

Fan-structure wave as a source of earthquake instability

Science.gov (United States)

Tarasov, Boris

2015-04-01

Today frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength at confined compression corresponding to the seismogenic layer. This determines the lithospheric strength and the primary earthquake mechanism associated with frictional stick-slip instability on pre-existing faults. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism the rock failure, associated with consecutive creation of small slabs (known as 'domino-blocks') from the intact rock in the rupture tip, is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new domino-blocks), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the lower limit of the lithospheric strength and favours the generation of new faults in pristine rocks in preference to frictional stick-slip instability along pre-existing faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created

K-pop Reception and Participatory Fan Culture in Austria

OpenAIRE

Sang-Yeon Sung

2013-01-01

K-pop’s popularity and its participatory fan culture have expanded beyond Asia and become significant in Europe in the past few years. After South Korean pop singer Psy’s “Gangnam Style” music video topped the Austrian chart in October 2012, the number and size of K-pop events in Austria sharply increased, with fans organizing various participatory events, including K-pop auditions, dance festivals, club meetings, quiz competitions, dance workshops, and smaller fan-culture gatherings. In the ...

An intelligent FFR with a self-adjustable ventilation fan.

Science.gov (United States)

Zhou, Song; Li, Hui; Shen, Shengnan; Li, Siyu; Wang, Wei; Zhang, Xiaotie; Yang, James

2017-11-01

This article presents an intelligent Filtering Facepiece Respirator (FFR) with a self-adjustable ventilation fan for improved comfort. The ventilation fan with an intelligent control aims to reduce temperature, relative humidity, and CO 2 concentrations inside the facepiece. Compared with a previous version of the FFR, the advantage of this new FFR is the intelligent control of the fan's rotation speed based on the change in temperature and relative humidity in the FFR dead space. The design of the control system utilizes an 8-bit, ultra-low power STC15W404AS microcontroller (HongJin technology, Shenzhen, China), and adopts a high-precision AM2320 device (AoSong electronic, Guangzhou, China) as temperature and relative humidity sensor so that control of temperature and relative humidity is realized in real time within the FFR dead space. The ventilation fan is intelligently driven and runs on a rechargeable lithium battery with a power-save mode that provides a correspondingly longer operational time. Meanwhile, the design is simplistic. Two experiments were performed to determine the best location to place the fan.

Submersible fans and pumps for cryogenic fluids

International Nuclear Information System (INIS)

Mark, J.W.

1986-01-01

Submersible electric motor driven fans of three sizes have been designed, built and operated at 21 0 K at the Stanford Linear Accelerator Center. The largest is a 100-mm diameter, 2 stage vaneaxial fan with a nominal capacity of 6 L/s at 2 m head. It is driven by a 4 pole, 3 phase induction motor that runs at 1750 rpm. The next smaller one is an 85-mm diameter centrifugal pump. It pumps 3 L/s at a head of 5 m. The third is a 75-mm single stage vaneaxial fan with a nominal capacity is 3 L/s at a head of 2 m. The 85-mm pump and the 75-mm fan are driven by 2 pole, 3 phase induction motors running at 3550 rpm. The motors were modified to operate submerged in the cryogenic fluid. The pumps have been operated in liquid hydrogen, liquid deuterium, and pressurized helium gas at 21 0 K. They can also operate with denser fluids such as liquid nitrogen, but rotational speed, capacity, and head will be reduced. They have been operated while submerged in liquid helium

Performance Testing Of A Modified Centrifugal Fan With Serrated Blade Impeller

OpenAIRE

Zaimar; Mursalim; H. Abbas; Supratomo

2017-01-01

Changes of shape dimension and component part of impeller might change of characteristic fluid flow so that pressure static in the fan housing changed. Changing some geometric characteristics of the centrifugal fan has more efficiency taking with energy crises into consideration. Several factors that can affect fan performance namely design and type size rotation speed air condition or gas through a fan operating point on the nature of the relationship between a volume of air flow and pressur...

A techno-typological analysis of fan (tabular scrapers from Ein Zippori, Israel

Directory of Open Access Journals (Sweden)

Katia Zutovski

2016-09-01

Full Text Available Fan (or tabular scrapers are a diagnostic  tool type in Chalcolithic Ghassulian and Early Bronze Age lithic assemblages from  the southern Levant. To date, only small numbers of fan scrapers have been reported from the Late Pottery Neolithic Wadi Rabah culture. In this paper we present a techno-typological analysis of a fair sample of fan scrapers and fan scrapers spalls from Wadi Rabah and Early Bronze Age layers at Ein Zippori, Lower Galilee, Israel. Techno-typological similarities and differences of Wadi Rabah, Chalcolithic Ghassulian and Early Bronze Age fan scrapers from Ein Zippori and other sites in the region are presented, trends of change along time are noted, and an updated definition is proposed. Our results indicate that fan scrapers are highly efficient tools for accurate and prolonged animal butchering and hide working. The main advantage of fan scrapers is their mostly flat, thin morphology and large size that permits the creation of several relatively long working edges, various retouched angles (from sharp to abrupt, extensive resharpening, and a comfortable grasp. While fan scrapers were products of a local trajectory in Late Pottery Neolithic Wadi Rabah lithic industries at Ein Zippori, a standardized, off-site manufacturing of fan scrapers is evident during the Early Bronze Age.

Geological aspects of paleoseismicity and archaeosismology in the fluvial alluvial Rimac valley

OpenAIRE

Jacay, Javier

2017-01-01

The sedimentary fill of the Rimac River fluvial-alluvial plain (Upper Miocene-Quaternary) consists of a thick sequence of unconsolidated material that corresponds to fluvial deposits. A record of seismotectonic activity is presentedin the sedimentary levels of fine facie within numerous paleoseismic structures such as contoured layers, pseudonodules, load figures, and material injections. Additionally, wall inclination and collapse, as well as displacement and partialfracturing, and pavement ...

Fan cooling of the resting area in a free stalls dairy barn

Science.gov (United States)

Calegari, Ferdinando; Calamari, Luigi; Frazzi, Ermes

2014-08-01

This summer study evaluated the effect of providing additional fans (cooling) in the resting area within a free-stall dairy barn that had fans and sprinklers in the feeding area and paddock availability. Thirty cows were divided into two homogenous groups and kept in two pens: one had the resting area equipped with two fans (FAN) while no fans were added to the other resting area (CON). Microclimatic parameters, rectal temperature (RT), breathing rate (BR), milk yield, and milk pH traits were recorded. Time budgeting and the behaviour of the cows (time spent in the feeding area, standing and lying in other areas) were also recorded using digital video technology. Two slight-to-moderate heat waves were observed. During the hottest period the daily maximum temperature recorded was 33.5 °C and the daily maximum THI was 81.6. During this period, the BR and RT increased only slightly in both groups, with lower BR (n.s.) in FAN compared with CON. Milk yield was better maintained (n.s.) in FAN compared with CON during the hottest period. The FAN cows showed a greater ( P FAN and CON, respectively), whereas CON cows made greater ( P fans in the resting area improves cow comfort, which increases use of the resting area. The lying time results also suggest that the benefits of providing ventilation in the resting area might be more evident in barns where there is no paddock.

Natural radionuclide behaviour in the fluvial environment

International Nuclear Information System (INIS)

Murray, A.S.; Olley, J.M.; Wallbrink, P.J.

1992-01-01

Variable concentrations of uranium and thorium series nuclides and 7 Be have been measured in soils and sediments. Strong correlations between 226 Ra and thorium series nuclides were found in sediments but not in soils. Laboratory measurements suggest the correlations arise from particle size and density dependent transport, and transport-related abrasion of iron oxide coatings. These correlations are characteristic of the sampled location, and provide a method for identifying the source areas which dominate the fluvial nuclide flux, and by implication, the associated sediment flux. Cosmogenic 7 Be (half-life 53 d) also contributes to nuclide fluxes. Over an 18 month period, individual rainstorms increased the 7 Be soil inventory by 10% on average. Dry precipitation contributed less than 10% to the total. Most 7 Be was retained within the top few millimetres of soil. It is deduced that 7 Be presence in fluvial sediments indicates a significant surface source contribution to the overall nuclide and sediment flux. (author)

Study on the performance improvement of multiblade fans. Effects of suction cones; Tayoku fan no seino kaizen ni kansuru kenkyu. Suction cone no eikyo

Energy Technology Data Exchange (ETDEWEB)

Kuratani, F.; Ogawa, T. [Hyogo University of Teacher Education, Hyogo (Japan); Yamamoto, S.

1999-07-25

In order to improve the performance of a multiblade fan, the effects of three types of suction cones of the fan casing on the fan efficiency and noise are investigated experimentally. The first type of the suction cone is the insertion type, which is inserted into the inside of the fan impeller. The second type is the extrusion type, which extrudes outside from the casing surface. The third type is the combination type of two types. The results of those three types are compared with those of the commonly used suction cone. The followings are made clear: (1) The insertion type and the extrusion type are effective in improving the efficiency and reducing noise. (2) The optimal lengths of the insertion and the extrusion exist. (3) The combination type is more effective in improving the efficiency. (4) The combination type with the skewed cutoff of the fan casing shows the best effect. (author)

The influence of fluvial reservoir architecture on geothermal energy production in Hot Sedimentary Aquifers

NARCIS (Netherlands)

Willems, C.J.L.

2014-01-01

Currently six geothermal doublets are realized in the WNB. Five of these doublets target the same Lower Cretaceous fluvial sandstone interval, the Nieuwerkerk Formation. About 40 exploration licences are granted. Many of them also have sandstones in the same fluvial interval, the Nieuwerkerk

Backprojection filtering for variable orbit fan-beam tomography

International Nuclear Information System (INIS)

Gullberg, G.T.; Zeng, G.L.

1995-01-01

Backprojection filtering algorithms are presented for three variable Orbit fan-beam geometries. Expressions for the fan beam projection and backprojection operators are given for a flat detector fan-beam geometry with fixed focal length, with variable focal length, and with fixed focal length and off-center focusing. Backprojection operators are derived for each geometry using transformation of coordinates to transform from a parallel geometry backprojector to a fan-beam backprojector for the appropriate geometry. The backprojection operator includes a factor which is a function of the coordinates of the projection ray and the coordinates of the pixel in the backprojected image. The backprojection filtering algorithm first backprojects the variable orbit fan-beam projection data using the appropriately derived backprojector to obtain a 1/r blurring of the original image then takes the two-dimensional (2D) Fast Fourier Transform (FFT) of the backprojected image, then multiples the transformed image by the 2D ramp filter function, and finally takes the inverse 2D FFT to obtain the reconstructed image. Computer simulations verify that backprojectors with appropriate weighting give artifact free reconstructions of simulated line integral projections. Also, it is shown that it is not necessary to assume a projection model of line integrals, but the projector and backprojector can be defined to model the physics of the imaging detection process. A backprojector for variable orbit fan-beam tomography with fixed focal length is derived which includes an additional factor which is a function of the flux density along the flat detector. It is shown that the impulse response for the composite of the projection and backprojection operations is equal to 1/r

Automatic Lamp and Fan Control Based on Microcontroller

Science.gov (United States)

Widyaningrum, V. T.; Pramudita, Y. D.

2018-01-01

In general, automation can be described as a process following pre-determined sequential steps with a little or without any human exertion. Automation is provided with the use of various sensors suitable to observe the production processes, actuators and different techniques and devices. In this research, the automation system developed is an automatic lamp and an automatic fan on the smart home. Both of these systems will be processed using an Arduino Mega 2560 microcontroller. A microcontroller is used to obtain values of physical conditions through sensors connected to it. In the automatic lamp system required sensors to detect the light of the LDR (Light Dependent Resistor) sensor. While the automatic fan system required sensors to detect the temperature of the DHT11 sensor. In tests that have been done lamps and fans can work properly. The lamp can turn on automatically when the light begins to darken, and the lamp can also turn off automatically when the light begins to bright again. In addition, it can concluded also that the readings of LDR sensors are placed outside the room is different from the readings of LDR sensors placed in the room. This is because the light intensity received by the existing LDR sensor in the room is blocked by the wall of the house or by other objects. Then for the fan, it can also turn on automatically when the temperature is greater than 25°C, and the fan speed can also be adjusted. The fan may also turn off automatically when the temperature is less than equal to 25°C.

Infrared thermography application on predictive maintenance for exhaust fan motor

International Nuclear Information System (INIS)

I Wayan Widiana; Jakaria; Artadi Heru; Mulyono

2013-01-01

To determine the condition of the exhaust fan motor in terms of heat dissipation, predictive maintenance needs to be done. One way is to use infrared thermography. The method used is an infrared thermography with qualitative technique which the analysis focused on the distribution patterns of heat captured by the infrared camera. From measurement results expected to be obtained data of the heat distribution occurs in the motor exhaust fan so it can be given treatment or further improvements recommendations to avoid failure of the operation. Results of measurements on the motor exhaust fan 9 and the motor exhaust fan 10 indicates that there is excessive heat dissipation (over heating). The recommendation given is increasing the motor capacity of 11 kW to 18 kW with a consideration of the addition load on exhaust fan system and age of motor more than 22 years. (author)

The mediating role of facebook fan pages.

Science.gov (United States)

Chih, Wen-Hai; Hsu, Li-Chun; Wang, Kai-Yu; Lin, Kuan-Yu

2014-01-01

Using the dual mediation hypothesis, this study investigates the role of interestingness (the power of attracting or holding one's attention) attitude towards the news, in the formation of Facebook Fan Page users' electronic word-of-mouth intentions. A total of 599 Facebook fan page users in Taiwan were recruited and structural equation modeling (SEM) was used to test the research hypotheses. The results show that both perceived news entertainment and informativeness positively influence interestingness attitude towards the news. Interestingness attitude towards the news subsequently influences hedonism and utilitarianism attitudes towards the Fan Page, which then influence eWOM intentions. Interestingness attitude towards the news plays a more important role than hedonism and utilitarianism attitudes in generating electronic word-of-mouth intentions. Based on the findings, the implications and future research suggestions are provided.

78 FR 25626 - Energy Conservation Program for Consumer Products: Energy Conservation Standards for Ceiling Fans...

Science.gov (United States)

2013-05-02

... Conservation Program for Consumer Products: Energy Conservation Standards for Ceiling Fans and Ceiling Fan... for residential ceiling fans and ceiling fan light kits in the Federal Register. This document... other aspect of the rulemaking for ceiling fans and ceiling fan light kits. The comment period is...

Terbentuknya Identitas Fans Sepak Bola sebagai Budaya Massa dalam Industri Media

Directory of Open Access Journals (Sweden)

Iswandi Syahputra

2016-12-01

Full Text Available Nowadays football is not merely sport. It has become industry, even popular culture. This happen because on the same time mass media grows into mass culture industry. The union of football and mass media as industry has melted few social and culture boundaries. Socially—through mass media—football had joined many social background into football fans identity, and it even connect all over the world. Football had transformed into popular culture that always moves in instability that drain its fans’s emotion. The football fans emotion in turn polarised into fans club which was created based on imaginary bound. Fans is the most visible part from text society and pop culture practice that could become fanatic. This fans fanatism phenomena could happen because the fans are pasif and patologic victim of mass media. This phenomena also mark the indication of transition from agricultural society into industrial and urban society.

A Field Exercise in Fluvial Sediment Transport.

Science.gov (United States)

Tharp, Thomas M.

1983-01-01

Describes an investigation which introduces the mathematical principles of stream hydraulics and fluvial sediment in a practical context. The investigation has four stages: defining hydrology of the stream; defining channel hydraulics in a study reach; measuring grain size; and calculating transportable grain size and comparing measure stream-bed…

Construction of an automated temperature sensing electric fan ...

African Journals Online (AJOL)

... electric fan indicate that there will be a great demand for the product if it is introduced to the market since everybody cannot afford an air-conditioner due to its high cost. Key words: Temperature, Fan Regulator, C++ programming, Analogue-to-Digital Converter (ADC), Micro-controller, Relay, Liquid Crystal Display (LCD).

"I'm Buffy, and you're history": Putting fan studies into history [editorial

Directory of Open Access Journals (Sweden)

Nancy Reagin

2011-03-01

Full Text Available This essay kicks off the special historical issue of Transformative Works and Cultures by offering an overview of the ways in which fan communities have been studied by academic historians, and how fan studies has written the history of fan communities. The essay discusses historical work done by amateur fan historians throughout the 20th century; what academic historians can offer fan communities; why academic historians could benefit from studying fandoms as part of the history of popular culture; and what fan studies as a discipline might gain from a broader historical analysis of fandoms.

The Star Wars franchise, fan edits, and Lucasfilm [symposium

Directory of Open Access Journals (Sweden)

Forrest Phillips

2012-03-01

Full Text Available Fan edits assert that fan authority is on par with that of a work's original creator; this authority is generated not only through the argument, but through the structure of the text itself. Fan edits adhere to classical filmmaking techniques, creating coherent plots and editing for continuity. These recut texts are emblematic of current ownership debates; they are the read/write culture brought to fandom. The Star Wars series of films are among the most frequently recut texts and are my focus here.

Turbine Engine with Differential Gear Driven Fan and Compressor

Science.gov (United States)

Suciu, Gabriel L. (Inventor); Pagluica, Gino J. (Inventor); Duong, Loc Quang (Inventor); Portlock, Lawrence E. (Inventor)

2013-01-01

A gas turbine engine provides a differential gear system coupling the turbine to the bypass fan and the compressor. In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear, which drives a planet carrier and a ring gear in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

Effect of inlet straighteners on centrifugal fan performance

Energy Technology Data Exchange (ETDEWEB)

Bayomi, N.N.; Abdel Hafiz, A. [Faculty of Engineering, Mataria, Helwan University, 11718 Masaken, El-Helmia, Cairo (Egypt); Osman, A.M. [Faculty of Engineering, Shoubra, Zagazig University, Cairo (Egypt)

2006-11-15

The use of straighteners in the inlet duct of centrifugal fans is suggested for eliminating any inlet distortion. An experimental investigation was performed to study the effect of inlet straighteners on the performance characteristics of centrifugal fans. Two types of straighteners were used, circular tubes and zigzag cross section, with different lengths. Circular tubes with different diameters have been investigated. The study was conducted on three types of fans, namely radial, backward with exit blade angles 60{sup o} and 75{sup o} and forward with 105{sup o} and 120{sup o}. The results confirm that the inlet straighteners exhibit different effects on the fan performance for the different blade angles. Accordingly, the results indicate the selection of long circular tube straighteners with large diameter for radial blades, long zigzag type for backward 60{sup o} blade angle and short zigzag type for backward 75{sup o} blade angle. Generally, good improvements in efficiency are observed for radial and backward blades on account of a slight drop in static head. In addition, an increase in the flow margin up to 12% and a decrease in the noise level from 3 to 5dB are indicated compared to the free inlet condition. On the contrary, unfavorable influences are exerted on the forward fan performance. (author)

Fan activism, cybervigilantism, and Othering mechanisms in K-pop fandom

Directory of Open Access Journals (Sweden)

Sun Jung

2012-06-01

Full Text Available Korean popular music (K-pop fandom may serve as a case study to identify both cynical and utopian views of fans' participatory Net activism by addressing three key aspects: fan activism, cybervigilantism, and Othering mechanisms. Fancom (fan company in the K-pop scene refers to the way fans systematically manage their own stars. These notions of assertive fancom practices address how fans actively participate in sociocultural events such as fund raising, donating to charity, and volunteering in emergency situations. This management may take another turn, however: antifandom surrounds K-pop star Tablo, signifying cybervigilantism of sinsang teolgi (personal information theft, a term referring to the online activities of a group of netizens who seek to expose the personal details of perceived wrongdoers by publishing them online as a form of punishment. The Tablo case revitalized public concern over privacy and the security of personal information in the digital era. Finally, Othering mechanisms in participatory online K-pop fandom display a strong sense of nationalism and even racism, as demonstrated by responses to anti-Korean rhetoric posted on the MySpace page of K-pop idol Jae-Beom. This highlights the relationship between participatory Net activism and nationalistic sentiment active within K-pop fandom. Some K-pop fan practices may have negative connotations, but by engaging with specific civic issues and social events, participatory fan practices encourage people to interact, discuss, and challenge conventional discourses, which may lead to new forms of social action.

Demonstration of Intelligent Control and Fan Improvements in Computer Room Air Handlers

Energy Technology Data Exchange (ETDEWEB)

Coles, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Greenberg, Steve [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Vita, Corinne [Vigilent, Oakland, CA (United States)

2012-11-30

This report documents a demonstration of the energy-efficiency improvement provided by a new control system for computer room air handling devices. It also analyzes measured and reported air handling device fan power associated with changing the fan type. A 135,000 square foot commercial data center was used for the demonstration. All air handling units were upgraded with improved efficiency fans, and a control system that automatically adjusts the fan speed for the air handling units was added. Power measurements were collected for a baseline and for a period with the fan speed control system active. Changing the fan type resulted in a savings of 47 percent of energy used by the air handling equipment and associated chiller plant energy needed to cool the air handlers themselves. The addition of the fan speed control resulted in an additional 37 percent savings in the same two categories. The combined savings for the two improvements for the same categories was 66 percent compared to the data center fitted with the original fans without a control system. The energy use reduction provided by the complete air handling device improvement program for the whole data center site is estimated to be 2.9 million kilowatt hours per year—an overall data center site savings of 8.0 percent. The reduced electrical energy use at the site provides a 1.9 million pound yearly reduction of carbon dioxide emissions. This demonstration showed that fan upgrades and a control system addition provide cost-effective improvements for data centers, with a payback reported to be under two years without utility incentives. In addition to the control system providing energy savings, the data collection and visual analysis capabilities provided immediate and long-term benefits. It is recommended that data center operators consider investing in fan upgrades and/or adding fan speed control for computer room air handlers.

On the design and structural analysis of jet engine fan blade structures

Science.gov (United States)

Amoo, Leye M.

2013-07-01

Progress in the design and structural analysis of commercial jet engine fan blades is reviewed and presented. This article is motivated by the key role fan blades play in the performance of advanced gas turbine jet engines. The fundamentals of the associated physics are emphasized. Recent developments and advancements have led to an increase and improvement in fan blade structural durability, stability and reliability. This article is intended as a high level review of the fan blade environment and current state of structural design to aid further research in developing new and innovative fan blade technologies.

The Eastern delta-fan deposits on the Granada Basin as tectonic indicators of the Sierra Nevada uplift (Betic Cordillera, South Spain)

Science.gov (United States)

Roldán, Francisco Javier; Azañon, Jose Miguel; Mateos, Rosa Maria

2014-05-01

A geological mapping in detail of the Eastern sector of the Granada Basin (South Spain) reveals two different groups of Gilbert delta-fans related to the Sierra Nevada uplift. The first group, in the southern part and with a surface of 6 km2, has three major coarsening-upward sequences. They are composed of very coarse deposits, those of conglomerates, sands and silts. Progradational strata units to the basin have been observed. The dominantly fluvial facies association has locally developed shallow marine foreset deposits (partially with reef colonization) as well as topset red soils (Dabrio, et al., 1978; Braga et a., 1990; García-García, et al., 1999) . All the sequences are discordant over marine facies (calcarenites) dated over 8,26 Ma (Late Tortonian). The second group, in the northern part and with an extension of 12 km2, has similar characteristics, but some of the boulders have ostreids and lamellibranchs species which reveal their former position in a previous marine environment. The Sierra Nevada uplift caused the remobilization of these boulders, being transported by debris-flow inside the delta-fan bodies (García-García, et al., 2006). The dating of ostreids shells with Sr techniques reveals ages over 7,13, 6,61 and 5,45 Ma, from the lower to the upper delta-fan deposits, which are related to the three main sequences observed and with three major tectonic pulses during the Late Miocene. These interpretations are in agreement with apatite fision-track studies carried out in some boulders of these coarse delta-fan deposits (Clark and Dempster, 2013). They reveal a detailed record of Neogene denudation from the Sierra Nevada basement and with uplift periods between 5,45Ma- 2 Ma. The latest pulses affected the delta-fan sediments given rise to new fan systems in the Granada Basin (Alhambra Formation). The thoroughly study of the Miocene delta-fan sediments allows us to conclude that they were related to a sin-sedimentary tectonic activity linked to the

The Challenges of Teaching Fan Studies

DEFF Research Database (Denmark)

Stephan, Matthias

, has only gained in popularity. Yet, the nature of the course in question, an interdisciplinary open elective, has meant a class with a variety of backgrounds, preparation, and expectations from fan studies and its critical apparatus. In addition, due to the course being taught in English, it attracts...... an abundance of exchange students, further complicating the course expectations. The paper will explore how different aspects of fan studies are presented, the variety and depth of theoretical approaches that are both available and suitable to the course, while at the same time exploring the difficulty...

"Past the brink of tacit support": Fan activism and the Whedonverses

Directory of Open Access Journals (Sweden)

Tanya R. Cochran

2012-06-01

Full Text Available For decades, the phrase fan activism has referred almost exclusively to television fans' efforts to save their favorite series. These campaigns—dating at least as far back as the original Star Trek (1966–69 to the more recent Farscape (1999–2003, Firefly (2002–3, Jericho (2006–8, and Veronica Mars (2004–7, among others—appear effective at catalyzing fan involvement, yet are largely ineffective at saving series. In other words, while it may achieve some secondary, albeit significant, victories such as tighter-knit relationships among fans, fan crusading rarely seems to end with the supposed primary goal of activist labors: more installments of the texts devotees admire and love. Recently, however, the phenomenon of fan activism has taken on a new dimension, and scholars are beginning to take note by asking several important questions. As Henry Jenkins asks, how does a fan move from "participatory culture to public participation"? And what does this move mean? As one might expect, there are many reasons for and implications that emerge from this reallocation of such devoted attention. To explore some of those reasons and implications, the author considers some of the devotees of television auteur Joss Whedon, their activist efforts, and the distinct ways Whedon inspires a politically participatory fan following. Ultimately, the author contends that through their activism, many enthusiasts of the Whedonverses extend the worlds of Whedon's stories by consciously constructing a sociopolitical, feminist identity.

Prediction of fan assisted flow in a duct/pipe network

International Nuclear Information System (INIS)

Quraishi, M.S.

1996-01-01

The commonly used fan+duct model is usually based on a table generated by matching the fan and system characteristic curves with the applied pressure drop across the fan+duct/pipe network and using linear or polynomial interpolation for intermediate values. However, this empirical approach can only handle a single system configuration for each table. If this approach is replaced by an algebraic formulation a general and flexible model can be developed. The algebraic model will be able to account for failure of resistances in the duct/pipe system as well as the failure of duct/pipe at an intermediate location. This paper presents the development of an algebraic model for fan+duct/pipe systems. (author)

The Fabulous Fact Fan.

Science.gov (United States)

Couch, Jene P.

1994-01-01

Discusses the use and construction of "fact fans," fun and easy-to-make manipulatives that provide elementary school students with the opportunity to explore mathematics operations being studied in the classroom and to practice addition, subtraction, multiplication, and division facts. (BB)

Fluvial facies reservoir productivity prediction method based on principal component analysis and artificial neural network

Directory of Open Access Journals (Sweden)

Pengyu Gao

2016-03-01

Full Text Available It is difficult to forecast the well productivity because of the complexity of vertical and horizontal developments in fluvial facies reservoir. This paper proposes a method based on Principal Component Analysis and Artificial Neural Network to predict well productivity of fluvial facies reservoir. The method summarizes the statistical reservoir factors and engineering factors that affect the well productivity, extracts information by applying the principal component analysis method and approximates arbitrary functions of the neural network to realize an accurate and efficient prediction on the fluvial facies reservoir well productivity. This method provides an effective way for forecasting the productivity of fluvial facies reservoir which is affected by multi-factors and complex mechanism. The study result shows that this method is a practical, effective, accurate and indirect productivity forecast method and is suitable for field application.

Hockey Fans in Training (Hockey FIT) pilot study protocol: a gender-sensitized weight loss and healthy lifestyle program for overweight and obese male hockey fans.

Science.gov (United States)

Gill, Dawn P; Blunt, Wendy; De Cruz, Ashleigh; Riggin, Brendan; Hunt, Kate; Zou, Guangyong; Sibbald, Shannon; Danylchuk, Karen; Zwarenstein, Merrick; Gray, Cindy M; Wyke, Sally; Bunn, Christopher; Petrella, Robert J

2016-10-19

Effective approaches that engage men in weight loss and lifestyle change are important because of worldwide increases, including in Canada, in obesity and chronic diseases. Football Fans in Training (FFIT), developed in Scotland, successfully tackled these problems by engaging overweight/obese male football fans in sustained weight loss and positive health behaviours, through program deliveries at professional football stadia. Aims: 1) Adapt FFIT to hockey within the Canadian context and integrate with HealtheSteps™ (evidence-based lifestyle program) to develop Hockey Fans in Training (Hockey FIT); 2) Explore potential for Hockey FIT to help overweight/obese men lose weight and improve other outcomes by 12 weeks, and retain these improvements to 12 months; 3) Evaluate feasibility of recruiting and retaining overweight/obese men; 4) Evaluate acceptability of Hockey FIT; and 5) Conduct program optimization via a process evaluation. We conducted a two-arm pilot pragmatic randomized controlled trial (pRCT) whereby 80 overweight/obese male hockey fans (35-65 years; body-mass index ≥28 kg/m 2 ) were recruited through their connection to two junior A hockey teams (London and Sarnia, ON) and randomized to Intervention (Hockey FIT) or Comparator (Wait-List Control). Hockey FIT includes a 12-week Active Phase (classroom instruction and exercise sessions delivered weekly by trained coaches) and a 40-week Maintenance Phase. Data collected at baseline and 12 weeks (both groups), and 12 months (Intervention only), will inform evaluation of the potential of Hockey FIT to help men lose weight and improve other health outcomes. Feasibility and acceptability will be assessed using data from self-reports at screening and baseline, program fidelity (program observations and coach reflections), participant focus group discussions, coach interviews, as well as program questionnaires and interviews with participants. This information will be analyzed to inform program

Experimental study on the mean flow characteristics of forward-curved centrifugal fans

International Nuclear Information System (INIS)

Kwon, Eui Yong; Cho, Nam Hyo

2001-01-01

Measurements have been made in an automotive HVAC blower for two different centrifugal fans. This work is directed at improving the performance of a conventional forward-curved centrifugal fan for a given small blower casing. Mean velocities and pressure have been measured using a miniature five-hole probe and a pressure scanning unit connected to an online data acquisition system. First, we obtained the fan performance curves versus flow rates showing a significant attenuation of unstable nature achieved with the new fan rotor in the surging operation range. Second, aerodynamic characterizations were carried out by investigating the velocity and pressure fields in the casing flow passage for different fan operating conditions. The measurements showed that performance coefficients are strongly influnced by flow characteristics at the throat region. The main flow features were common in both fans, but improved performance is achieved with the new fan rotor, particularly in lower flow rate regions. Based on the measured results, design improvements were carried out in an acceptable operation range, which gave considerable insight into what features of flow behavior were most important

Sherlockology and Galactica.tv: Fan sites as gifts or exploited labor?

Directory of Open Access Journals (Sweden)

Bertha Chin

2014-03-01

Full Text Available Current scholarship on fandom has been preoccupied with examining the changing relationship between media industry professionals and fans. Media producers, celebrities, and industry insiders are increasingly establishing contact with fans, bypassing traditional media entertainment outlets to provide them with information directly. This contact is facilitated by social media networks. Fans serve as grassroots campaigners, promoters, and sometimes even public relations officers, acting as liaisons between media producers, celebrities, or industry insiders and fandom in general. In doing so, they take on roles traditionally fulfilled by professional PR and marketing personnel, and they do it for free, resulting in accusations that they are being exploited for their labor. However, fans do not necessarily view themselves as being exploited. We need to consider the possibility that they may regard their contributions as a service—or gift—to fandom. In examining the roles played by two popular fan sites, Sherlockology and Galactica.tv, I propose to examine how fan labor may be considered an act of gift giving in fandom.

Feature Augmentation via Nonparametrics and Selection (FANS) in High-Dimensional Classification.

Science.gov (United States)

Fan, Jianqing; Feng, Yang; Jiang, Jiancheng; Tong, Xin

We propose a high dimensional classification method that involves nonparametric feature augmentation. Knowing that marginal density ratios are the most powerful univariate classifiers, we use the ratio estimates to transform the original feature measurements. Subsequently, penalized logistic regression is invoked, taking as input the newly transformed or augmented features. This procedure trains models equipped with local complexity and global simplicity, thereby avoiding the curse of dimensionality while creating a flexible nonlinear decision boundary. The resulting method is called Feature Augmentation via Nonparametrics and Selection (FANS). We motivate FANS by generalizing the Naive Bayes model, writing the log ratio of joint densities as a linear combination of those of marginal densities. It is related to generalized additive models, but has better interpretability and computability. Risk bounds are developed for FANS. In numerical analysis, FANS is compared with competing methods, so as to provide a guideline on its best application domain. Real data analysis demonstrates that FANS performs very competitively on benchmark email spam and gene expression data sets. Moreover, FANS is implemented by an extremely fast algorithm through parallel computing.

The role of meltwater in high-latitude trough-mouth fan development : the Disko Trough-Mouth Fan, West Greenland.

OpenAIRE

Cofaigh, Colm Ó.; Hogan, Kelly A.; Jennings, Anne E.; Callard, S. Louise; Dowdeswell, Julian A.; Noormets, Riko; Evans, Jeff

2018-01-01

The Disko Trough-Mouth Fan (TMF) is a major submarine sediment fan located along the central west Greenland continental margin offshore of Disko Trough. The location of the TMF at the mouth of a prominent cross-shelf trough indicates that it is a product of repeated glacigenic sediment delivery from former fast-flowing outlets of the Greenland Ice Sheet, including an ancestral Jakobshavn Isbrae, which expanded to the shelf edge during successive glacial cycles. This study focuses on the upper...

Applying fluvial geomorphology to river channel management: Background for progress towards a palaeohydrology protocol

Science.gov (United States)

Gregory, K. J.; Benito, G.; Downs, P. W.

2008-06-01

Significant developments have been achieved in applicable and applied fluvial geomorphology as shown in publications of the last three decades, analyzed as the basis for using results of studies of environmental change as a basis for management. The range of types of publications and of activities are more pertinent to river channel management as a result of concern with sustainability, global climate change, environmental ethics, ecosystem health concepts and public participation. Possible applications, with particular reference to river channel changes, include those concerned with form and process, assessment of channel change, urbanization, channelization, extractive industries, impact of engineering works, historical changes in land use, and restoration with specific examples illustrated in Table 1. In order to achieve general significance for fluvial geomorphology, more theory and extension by modelling methods is needed, and examples related to morphology and process characteristics, integrated approaches, and changes of the fluvial system are collected in Table 2. The ways in which potential applications are communicated to decision-makers range from applicable outputs including publications ranging from review papers, book chapters, and books, to applied outputs which include interdisciplinary problem solving, educational outreach, and direct involvement, with examples summarized in Table 3. On the basis of results gained from investigations covering periods longer than continuous records, a protocol embracing palaeohydrological inputs for application to river channel management is illustrated and developed as a synopsis version (Table 4), demonstrating how conclusions from geomorphological research can be expressed in a format which can be considered by managers.

78 FR 16443 - Energy Efficiency Program for Consumer Products: Energy Conservation Standards for Ceiling Fans...

Science.gov (United States)

2013-03-15

... Standards for Ceiling Fans and Ceiling Fan Light Kits AGENCY: Office of Energy Efficiency and Renewable... consider amending the energy conservation standards for ceiling fans and ceiling fan light kits. DOE also....gov . Follow the instructions for submitting comments. Email: CeilingFan[email protected

Broadband Liner Optimization for the Source Diagnostic Test Fan

Science.gov (United States)

Nark, Douglas M.; Jones, Michael G.

2012-01-01

The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

La géoarchéologie fluviale

Directory of Open Access Journals (Sweden)

Gilles Arnaud-Fassetta

2008-03-01

Full Text Available Les recherches des hydrogéomorphologues ont des applications nombreuses dans le vaste champ des sciences géoarchéologiques. Elles fournissent des réponses précises sur la façon dont l’environnement des anciens lieux de passage et de vie humaine a évolué. Le propos n’est pas seulement de définir les causes des grands changements environnementaux, mais aussi de juger de la vulnérabilité sociétale face aux contraintes hydroclimatiques. Pour cela, les méthodes d’étude doivent nécessairement prendre en compte les trois facettes de la géomorphologie fluviale : la paléohydrographie, la paléohydrologie et la paléohydraulique. La pertinence de cette approche est montrée en milieu rural et urbain dans les plaines deltaïques du Rhône (France du Sud et de l’Isonzo (Italie du Nord.Current research led by hydrogeomorphologists has numerous applications in the vast field of geoarchaeological sciences. It brings precise answers on environmental characteristics around the ancient places of passage and human life. The goal is not only to define the causes of global environmental changes, but also to precise the links between river dynamics and human societies in terms of fluvial risk. Therefore, the studied methods should simultaneously take into account the three facets of the fluvial geomorphology, i.e., the palaeohydrography, the palaeohydrology, and the palaeohydraulics. The pertinence of this combinatorial approach is deduced from the work of the author led both in rural and urban areas of the deltaic plains of the Rhône (South of France and Isonzo (northern Italy rivers.

Fundamental investigation on the impact strength of hollow fan blades

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T; Miyachi, T; Sofue, Y

1985-01-01

Models of hollow fan blades were made and tested to prove that their strength is sufficient for use in real engines. The hollow blades were fabricated by diffusion bonding of two titanium alloy (6Al-4V-Ti) plates, one of which had three spanwise stiffners and the other being flat plate. The model as a nontwisted tapered blade. Impact tests were carried out on the hollow fan blade models in which the ingestion of a 1.5 pounds bird was simulated. Solid blades with the same external form were also tested by similar methods for comparison. The results of these tests show that properly designed hollow blades have sufficient stiffness and strength for use as fan blades in the turbo-fan engine.

Fluvial processes and channel morphometry of the upper Orashi ...

African Journals Online (AJOL)

Fluvial processes and channel morphometry of the upper Orashi basin in ... of channel equilibrium between morphology and hydrology, the Orashi channel is not well ... Drainage basins, watershed morphology, morphometric analysis, Nigeria ...

Optimism Bias in Fans and Sports Reporters.

Science.gov (United States)

Love, Bradley C; Kopeć, Łukasz; Guest, Olivia

2015-01-01

People are optimistic about their prospects relative to others. However, existing studies can be difficult to interpret because outcomes are not zero-sum. For example, one person avoiding cancer does not necessitate that another person develops cancer. Ideally, optimism bias would be evaluated within a closed formal system to establish with certainty the extent of the bias and the associated environmental factors, such that optimism bias is demonstrated when a population is internally inconsistent. Accordingly, we asked NFL fans to predict how many games teams they liked and disliked would win in the 2015 season. Fans, like ESPN reporters assigned to cover a team, were overly optimistic about their team's prospects. The opposite pattern was found for teams that fans disliked. Optimism may flourish because year-to-year team results are marked by auto-correlation and regression to the group mean (i.e., good teams stay good, but bad teams improve).

Scattered radiation in fan beam imaging systems

International Nuclear Information System (INIS)

Johns, P.C.; Yaffe, M.

1982-01-01

Scatter-to-primary energy fluence ratios (S/P) have been studied for fan x-ray beams as used in CT scanners and slit projection radiography systems. The dependence of S/P on phantom diameter, distance from phantom to image receptor, and kilovoltage is presented. An empirical equation is given that predicts S/P over a wide range of fan beam imaging configurations. For CT body scans on a 4th-generation machine, S/P is approximately 5%. Scattered radiation can produce a significant cupping artefact in CT images which is similar to that due to beam hardening. When multiple slices are used in scanned slit radiography, they can be arranged such that the increase in S/P is negligible. Calculations of scatter-to-primary ratios for first order scattering showed that for fan beams the contribution of coherent scatter is comparable to or greater than that of incoherent first scatter

Homophobia, heteronormativity, and slash fan fiction

Directory of Open Access Journals (Sweden)

April S. Callis

2016-09-01

Full Text Available I analyze the relationship between homophobia/heteronormativity and slash fan fiction. Through reading and coding almost 6,000 pages of Kirk/Spock fan fiction written from 1978 to 2014, I illuminate shifts in how normative gender and sexuality are portrayed by K/S authors. Writers of K/S, while ostensibly writing about the 23rd century, consciously or unconsciously include cultural norms from the 20th and 21st centuries. Thus, slash becomes a lens through which readers can view a decrease in both homophobia and heteronormativity in US culture over the past several decades.

Development of a miniature fan motor

Science.gov (United States)

Wang, Chien-Chang; Yao, Yeong-Der; Liang, Kun-Yi; Huang, Chung-Chun; Chang, Yu-Choung

2012-04-01

A novel compact axial flux fan motor was developed. Such a micromotor could be a potential candidate for using as the cooling solution for the next generation mobile devices, for example, smart phones and pico-projectors. The key parameters of the motor, such as back electromotive force, cogging torque, and axial preload are predicted using finite element method. In addition, new approaches are proposed to measure these items, and the corresponding experimental results are in good agreement with the simulated one. Moreover, the undesired vibration harmonic is successfully suppressed, and the fan motor represents a high static pressure and air flow rate.

Quantifying relief on alluvial fans using airborne lidar to reveal patterns of sediment accumulation

Science.gov (United States)

Morelan, A. E., III; Oskin, M. E.

2017-12-01

We present a method of quantifying detailed surface relief on alluvial fans from high-resolution topography. Average slope and curvature of the fan are used together to empirically derive an idealized, radially symmetric fan surface, from which we compute residual topography. Maps produced using this technique highlight spatial patterns of fan deposition and avulsion. Regions of high residual topography reveal active and abandoned sediment lobes accumulated from recent depositional events, often with well-defined channels at their apex. Preliminary observations suggest that surface relief is uniform across a collection of fans in a given region and source lithology. Alluvial fans with granitic catchment lithologies in eastern California (n=12), each with varying source catchment size and mean fan slope, all show relief of around 4 meters. A collection of fans from the Carrizo Plain in central California (n=12), with source catchments set within Miocene marine and nonmarine sedimentary rocks, show significantly lower relief values around 2 meters. We hypothesize that particle grain size determines this contrasting relief through its control on the thickness of fan-building debris flows. In both settings we find that sediment lobes tend to extend toward the fan toe. This pattern supports a process, observed in analog experiments, of fan deposition dominated by back-filling and overtopping of distributary channels by debris-flows.

Reverse Flow Engine Core Having a Ducted Fan with Integrated Secondary Flow Blades

Science.gov (United States)

Kisska, Michael K. (Inventor); Princen, Norman H. (Inventor); Kuehn, Mark S. (Inventor); Cosentino, Gary B. (Inventor)

2014-01-01

Secondary air flow is provided for a ducted fan having a reverse flow turbine engine core driving a fan blisk. The fan blisk incorporates a set of thrust fan blades extending from an outer hub and a set of integral secondary flow blades extending intermediate an inner hub and the outer hub. A nacelle provides an outer flow duct for the thrust fan blades and a secondary flow duct carries flow from the integral secondary flow blades as cooling air for components of the reverse flow turbine engine.

An investigation of FLUENT's fan model including the effect of swirl velocity

International Nuclear Information System (INIS)

El Saheli, A.; Barron, R.M.

2002-01-01

The purpose of this paper is to investigate and discuss the reliability of simplified models for the computational fluid dynamics (CFD) simulation of air flow through automotive engine cooling fans. One of the most widely used simplified fan models in industry is a variant of the actuator disk model which is available in most commercial CFD software, such as FLUENT. In this model, the fan is replaced by an infinitely thin surface on which pressure rise across the fan is specified as a polynomial function of normal velocity or flow rate. The advantages of this model are that it is simple, it accurately predicts the pressure rise through the fan and the axial velocity, and it is robust

Ridge Orientations of the Ridge-Forming Unit, Sinus Meridiani, Mars-A Fluvial Explanation

Science.gov (United States)

Wilkinson, M. Justin; Herridge, A.

2013-01-01

Imagery and MOLA data were used in an analysis of the ridge-forming rock unit (RFU) exposed in Sinus Meridiani (SM). This unit shows parallels at different scales with fluvial sedimentary bodies. We propose the terrestrial megafan as the prime analog for the RFU, and likely for other members of the layered units. Megafans are partial cones of fluvial sediment, with radii up to hundreds of km. Although recent reviews of hypotheses for the RFU units exclude fluvial hypotheses [1], inverted ridges in the deserts of Oman have been suggested as putative analogs for some ridges [2], apparently without appreciating The wider context in which these ridges have formed is a series of megafans [3], a relatively unappreciated geomorphic feature. It has been argued that these units conform to the megafan model at the regional, subregional and local scales [4]. At the regional scale suites of terrestrial megafans are known to cover large areas at the foot of uplands on all continents - a close parallel with the setting of the Meridiani sediments at the foot of the southern uplands of Mars, with its incised fluvial systems leading down the regional NW slope [2, 3] towards the sedimentary units. At the subregional scale the layering and internal discontinuities of the Meridiani rocks are consistent, inter alia, with stacked fluvial units [4]. Although poorly recognized as such, the prime geomorphic environment in which stream channel networks cover large areas, without intervening hillslopes, is the megafan [see e.g. 4]. Single megafans can reach 200,000 km2 [5]. Megafans thus supply an analog for areas where channel-like ridges (as a palimpsest of a prior landscape) cover the intercrater plains of Meridiani [6]. At the local, or river-reach scale, the numerous sinuous features of the RFU are suggestive of fluvial channels. Cross-cutting relationships, a common feature of channels on terrestrial megafans, are ubiquitous. Desert megafans show cemented paleo-channels as inverted

Traditional transformations and transmedial affirmations: Blurring the boundaries of Sherlockian fan practices

Directory of Open Access Journals (Sweden)

Ashley D. Polasek

2017-03-01

Full Text Available The modes of discourse employed by fans of Sherlock Holmes represent both affirmational and transformational impulses. As the fan community has grown and diversified, tensions have arisen between Sherlockians who prefer to utilize traditional frameworks dating back to the early practices of the Baker Street Irregulars in the 1930s and '40s and those who operate primarily in virtual spaces and utilize 21st-century digital platforms as frameworks for their discourse. Because the demographics of affirmational fans tend to align with those of fans preferring traditional frameworks, and conversely, the demographics of transformational fans tend to align with those of fans preferring transmedial frameworks, the styles of engagement often become conflated with the impulses driving the discourse itself. By first examining these tensions and then utilizing case studies that illustrate the four combinations of frameworks and modes of discourse—traditional-affirmational, transmedial-affirmational, traditional-transformational, and transmedial-transformational—I seek to complicate the boundaries that appear to divide the larger Sherlock Holmes fan community. I will demonstrate that the twin fannish impulses to affirm the text and transform it have operated not at odds but in parallel throughout the history of the fandom.

A model of plant strategies in fluvial hydrosystems

NARCIS (Netherlands)

Bornette, G.; Tabacchi, E.; Hupp, C.; Puijalon, S.; Rostan, J.C.

2008-01-01

1. We propose a model of plant strategies in temperate fluvial hydrosystems that considers the hydraulic and geomorphic features that control plant recruitment, establishment and growth in river floodplains. 2. The model describes first how the disturbance gradient and the grain-size of the river

First Test of Fan Active Noise Control (ANC) Completed

Science.gov (United States)

2005-01-01

With the advent of ultrahigh-bypass engines, the space available for passive acoustic treatment is becoming more limited, whereas noise regulations are becoming more stringent. Active noise control (ANC) holds promise as a solution to this problem. It uses secondary (added) noise sources to reduce or eliminate the offending noise radiation. The first active noise control test on the low-speed fan test bed was a General Electric Company system designed to control either the exhaust or inlet fan tone. This system consists of a "ring source," an induct array of error microphones, and a control computer. Fan tone noise propagates in a duct in the form of spinning waves. These waves are detected by the microphone array, and the computer identifies their spinning structure. The computer then controls the "ring source" to generate waves that have the same spinning structure and amplitude, but 180 out of phase with the fan noise. This computer generated tone cancels the fan tone before it radiates from the duct and is heard in the far field. The "ring source" used in these tests is a cylindrical array of 16 flat-plate acoustic radiators that are driven by thin piezoceramic sheets bonded to their back surfaces. The resulting source can produce spinning waves up to mode 7 at levels high enough to cancel the fan tone. The control software is flexible enough to work on spinning mode orders from -6 to 6. In this test, the fan was configured to produce a tone of order 6. The complete modal (spinning and radial) structure of the tones was measured with two builtin sets of rotating microphone rakes. These rakes provide a measurement of the system performance independent from the control system error microphones. In addition, the far-field noise was measured with a semicircular array of 28 microphones. This test represents the first in a series of tests that demonstrate different active noise control concepts, each on a progressively more complicated modal structure. The tests are

Numerical Study of Transition of an Annular Lift Fan Aircraft

OpenAIRE

Yun Jiang; Bo Zhang

2016-01-01

The present study aimed at studying the transition of annular lift fan aircraft through computational fluid dynamics (CFD) simulations. The oscillations of lift and drag, the optimization for the figure of merit, and the characteristics of drag, yawing, rolling and pitching moments in transition are studied. The results show that a two-stage upper and lower fan lift system can generate oscillations of lift and drag in transition, while a single-stage inner and outer fan lift system can elimin...

Prediction and Reduction of Aerodynamic Noise of the Multiblade Centrifugal Fan

Directory of Open Access Journals (Sweden)

Shuiqing Zhou

2014-08-01

Full Text Available An aerodynamic and aeroacoustic investigation of the multiblade centrifugal fan is proposed in this paper, and a hybrid technique of combining flow field calculation and acoustic analysis is applied to solve the aeroacoustic problem of multiblade centrifugal fan. The unsteady flow field of the multiblade centrifugal fan is predicted by solving the incompressible Reynolds-averaged Navier-Stokes (RANS equations with conventional computing techniques for fluid dynamics. The principal noise source induced is extracted from the calculation of the flow field by using acoustic principles, and the modeled sources on inner and outer surfaces of the volute are calculated with multiregional boundary element method (BEM. Through qualitative analysis, the sound pressure amplitude distribution of the multiblade centrifugal fan in near field is given and the sound pressure level (SPL spectrum diagram of monitoring points in far field is obtained. Based on the analysis results, the volute tongue structure is adjusted and then a low-noise design for the centrifugal fan is proposed. The comparison of noise tests shows the noise reduction of improved fan model is more obvious, which is in good agreement with the prediction using the hybrid techniques.

The noise power spectrum in CT with direct fan beam reconstruction

International Nuclear Information System (INIS)

Baek, Jongduk; Pelc, Norbert J.

2010-01-01

The noise power spectrum (NPS) is a useful metric for understanding the noise content in images. To examine some unique properties of the NPS of fan beam CT, the authors derived an analytical expression for the NPS of fan beam CT and validated it with computer simulations. The nonstationary noise behavior of fan beam CT was examined by analyzing local regions and the entire field-of-view (FOV). This was performed for cases with uniform as well as nonuniform noise across the detector cells and across views. The simulated NPS from the entire FOV and local regions showed good agreement with the analytically derived NPS. The analysis shows that whereas the NPS of a large FOV in parallel beam CT (using a ramp filter) is proportional to frequency, the NPS with direct fan beam FBP reconstruction shows a high frequency roll off. Even in small regions, the fan beam NPS can show a sharp transition (discontinuity) at high frequencies. These effects are due to the variable magnification and therefore are more pronounced as the fan angle increases. For cases with nonuniform noise, the NPS can show the directional dependence and additional effects.

Unsteady Flow Dynamics and Acoustics of Two-Outlet Centrifugal Fan Design

Science.gov (United States)

Wong, I. Y. W.; Leung, R. C. K.; Law, A. K. Y.

2011-09-01

In this study, a centrifugal fan design with two flow outlets is investigated. This design aims to provide high mass flow rate but low noise performance. Two dimensional unsteady flow simulation with CFD code (FLUENT 6.3) is carried out to analyze the fan flow dynamics and its acoustics. The calculations were done using the unsteady Reynolds averaged Navier Stokes (URANS) approach in which effects of turbulence were accounted for using κ-ɛ model. This work aims to provide an insight how the dominant noise source mechanisms vary with a key fan geometrical paramters, namely, the ratio between cutoff distance and the radius of curvature of the fan housing. Four new fan designs were calculated. Simulation results show that the unsteady flow-induced forces on the fan blades are found to be the main noise sources. The blade force coefficients are then used to build the dipole source terms in Ffowcs Williams and Hawkings (FW-H) Equation for estimating their noise effects. It is found that one design is able to deliver a mass flow 34% more, but with sound pressure level (SPL) 10 dB lower, than the existing design .

ENERGY STAR Certified Ventilating Fans

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of...

Wordplay, mindplay: Fan fiction and postclassical narratology

Directory of Open Access Journals (Sweden)

Veerle Van Steenhuyse

2014-09-01

Full Text Available Recent narrative theories on story worlds, or the worlds evoked by narratives, call attention to the process of fan reading and the role which the canon plays in that process. This paper posits that such theories can help us understand literary techniques that make a difference on the level of the reading experience that is implied by fan fiction texts. This is illustrated with a close reading of Naguabo's "The Mother of All Marriage Proposals," a Jane Austen fic.

A Fan Solution for the Philips Airfryer

OpenAIRE

Gibernau Torres, Octavi

2012-01-01

The thesis on hand has been carried out at Philips Consumer Lifestyle Drachten that, together with Delft University of Technology, aims to develop a computed tool that determines the performance and efficiency curve of any centrifugal fan operating in the Philips Airfryer. The Airfryer is a Philips kitchen appliance that, thanks to the use of Rapid Air Technology, enables to fry food with a reduction of unhealthy fat up to 80%. Philips aims at reducing the total cost of the cooking fan an...

A geologic approach to field methods in fluvial geomorphology

Science.gov (United States)

Fitzpatrick, Faith A.; Thornbush, Mary J; Allen, Casey D; Fitzpatrick, Faith A.

2014-01-01

A geologic approach to field methods in fluvial geomorphology is useful for understanding causes and consequences of past, present, and possible future perturbations in river behavior and floodplain dynamics. Field methods include characterizing river planform and morphology changes and floodplain sedimentary sequences over long periods of time along a longitudinal river continuum. Techniques include topographic and bathymetric surveying of fluvial landforms in valley bottoms and describing floodplain sedimentary sequences through coring, trenching, and examining pits and exposures. Historical sediment budgets that include floodplain sedimentary records can characterize past and present sources and sinks of sediment along a longitudinal river continuum. Describing paleochannels and floodplain vertical accretion deposits, estimating long-term sedimentation rates, and constructing historical sediment budgets can assist in management of aquatic resources, habitat, sedimentation, and flooding issues.

Locating and Quantifying Broadband Fan Sources Using In-Duct Microphones

Science.gov (United States)

Dougherty, Robert P.; Walker, Bruce E.; Sutliff, Daniel L.

2010-01-01

In-duct beamforming techniques have been developed for locating broadband noise sources on a low-speed fan and quantifying the acoustic power in the inlet and aft fan ducts. The NASA Glenn Research Center's Advanced Noise Control Fan was used as a test bed. Several of the blades were modified to provide a broadband source to evaluate the efficacy of the in-duct beamforming technique. Phased arrays consisting of rings and line arrays of microphones were employed. For the imaging, the data were mathematically resampled in the frame of reference of the rotating fan. For both the imaging and power measurement steps, array steering vectors were computed using annular duct modal expansions, selected subsets of the cross spectral matrix elements were used, and the DAMAS and CLEAN-SC deconvolution algorithms were applied.

Towards a three-component model of fan loyalty: a case study of Chinese youth.

Directory of Open Access Journals (Sweden)

Xiao-xiao Zhang

Full Text Available The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

Towards a three-component model of fan loyalty: a case study of Chinese youth.

Science.gov (United States)

Zhang, Xiao-xiao; Liu, Li; Zhao, Xian; Zheng, Jian; Yang, Meng; Zhang, Ji-qi

2015-01-01

The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

Implications from Sedimentary records in Fluvial Terraces for Geomorphological Evolution in the Puli Basin, Taiwan

NARCIS (Netherlands)

Tseng, C.H.; Wenske, D.; Böse, M.; Reimann, T.; Lüthgens, C.; Frechen, Manfred

2013-01-01

Fluvial terraces play an important role for research on previous geomorphic processes as their sediments can record various sedimentation stages. In the mountains of central Taiwan, however, the formation time of sediments in the Puli Basin is still unclear. In this study, we investigate the fluvial

Optimism Bias in Fans and Sports Reporters

Science.gov (United States)

Love, Bradley C.

2015-01-01

People are optimistic about their prospects relative to others. However, existing studies can be difficult to interpret because outcomes are not zero-sum. For example, one person avoiding cancer does not necessitate that another person develops cancer. Ideally, optimism bias would be evaluated within a closed formal system to establish with certainty the extent of the bias and the associated environmental factors, such that optimism bias is demonstrated when a population is internally inconsistent. Accordingly, we asked NFL fans to predict how many games teams they liked and disliked would win in the 2015 season. Fans, like ESPN reporters assigned to cover a team, were overly optimistic about their team’s prospects. The opposite pattern was found for teams that fans disliked. Optimism may flourish because year-to-year team results are marked by auto-correlation and regression to the group mean (i.e., good teams stay good, but bad teams improve). PMID:26352146

Combined fluvial and pluvial urban flood hazard analysis: concept development and application to Can Tho city, Mekong Delta, Vietnam

Science.gov (United States)

Apel, Heiko; Martínez Trepat, Oriol; Nghia Hung, Nguyen; Thi Chinh, Do; Merz, Bruno; Viet Dung, Nguyen

2016-04-01

Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either a fluvial or pluvial flood hazard, studies of a combined fluvial and pluvial flood hazard are hardly available. Thus this study aims to analyse a fluvial and a pluvial flood hazard individually, but also to develop a method for the analysis of a combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as an example. In this tropical environment the annual monsoon triggered floods of the Mekong River, which can coincide with heavy local convective precipitation events, causing both fluvial and pluvial flooding at the same time. The fluvial flood hazard was estimated with a copula-based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. The pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data and a stochastic rainstorm generator. Inundation for all flood scenarios was simulated by a 2-dimensional hydrodynamic model implemented on a Graphics Processing Unit (GPU) for time-efficient flood propagation modelling. The combined fluvial-pluvial flood scenarios were derived by adding rainstorms to the fluvial flood events during the highest fluvial water levels. The probabilities of occurrence of the combined events were determined assuming independence of the two flood types and taking the seasonality and probability of

Ephemeral-fluvial sediments as potential hydrocarbon reservoirs. Vol. 1: Sedimentology

Energy Technology Data Exchange (ETDEWEB)

Taylor, K.S.

1994-12-31

Although reservoirs formed from ephemeral-fluvial sandstones have previously been considered relatively simple, unresolved problems of sandbody correlation and production anomalies demonstrate the need for improved understanding of their internal complexity. Outcropping ephemeral-fluvial systems have been studied in order to determine the main features and processes occurring in sand-rich ephemeral systems and to identify which features will be of importance in a hydrocarbon reservoir. The Lower Jurassic Upper Moenave and Kayenta Formations of south-eastern Utah and northern Arizona comprise series of stacked, sand-dominated sheet-like palaeochannels suggestive of low sinuosity, braided systems. Low subsidence rates and rapid lateral migration rates enabled channels to significantly modify their widths during high discharge. (author)

Radon concentration in the springs of the alluvial fan

International Nuclear Information System (INIS)

Horiuchi, Kimiko; Ishii, Tadashi; Kobayashi, Masao

2003-01-01

Rokugo alluvial fan is one of the typical stratified alluvial fans which have grown in the east edge of Yokote basin in Akita Prefecture. Many of Rokugo's springs are gushing out from 45 m to 50 m above the sea level where city town have been developed. Mechanism of gushing out of spring is closely bound up with the landform of this area. There is nearly no radon existing in the surface water, but in groundwater, radon concentrations are stable in every stratums and infiltration of groundwater to surface water. We would like to obtain some hydrological information by measuring radon concentration in water samples of Rokugo alluvial fan. (author)

Channel systems and lobe construction in the Mississippi Fan

Science.gov (United States)

Garrison, L. E.; Kenyon, Neil H.; Bouma, A.H.

1982-01-01

Morphological features on the Mississippi Fan in the eastern Gulf of Mexico were mapped using GLORIA II, a long-range side-scan sonar system. Prominent is a sinuous channel flanked by well-developed levees and occasional crevasse splays. The channel follows the axis and thickest part of the youngest fan lobe; seismic-reflection profiles offer evidence that its course has remained essentially constant throughout lobe development. Local modification and possible erosion of levees by currents indicates a present state of inactivity. Superficial sliding has affected part of the fan lobe, but does not appear to have been a factor in lobe construction. ?? 1982 A. M. Dowden, Inc.

Identifying core, exciting, and hybrid attributes in fans' assessments of major (World Cup) spectator sports events.

Science.gov (United States)

Gau, Li-Shiue

2013-12-01

This paper adopts a methodology of asymmetrical analyses to investigate the relevant importance of spectator sport attributes in terms of their non-linear associations with the benefits that fans experience while watching sports. Questionnaires tapping 16 attributes (e.g., teamwork, sportsmanship, level of competition) and 16 benefits (e.g., good mood, exciting experience, support for my favorite team) were distributed to a sample of fans at the outdoor broadcast of the 2010 World Cup final game at the National Stadium in Kaohsiung, Taiwan. 427 participants rated the importance and benefit of each attribute experienced from watching the game. Attributes were categorized as core, exciting, or hybrid attributes. The star player was the core attribute; rivalry, popularity, and coach were the exciting attributes; and the other 12 attributes were hybrid. Two-dimensional space analyses showed that attributes "sportsmanship, teamwork, and supporting a team" were both explicitly and implicitly important attributes. The methodology of asymmetrical analyses can help managers prioritize the focus of attributes and allocate resources effectively.

ENERGY STAR Certified Ceiling Fans

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1,...

Aeroacoustic measurements for an axial fan in a non-anechoic environment

International Nuclear Information System (INIS)

Davoudi, Behdad; Foss, John F; Morris, Scott C

2016-01-01

Determination of the aeroacoustic emission from an axial fan in a non-anechoic environment is a challenging experimental task given ambient noise and acoustic reflections from surrounding objects. Successful strategies to address this task for a representative nine and three blade fan are presented. An array consisting of ten microphones was constructed and placed in the upstream region of the axial fans to measure the fan acoustic signature at ten distinct locations. A novel delay and sum (DS) beamforming technique (that allows precise time delays to be established by the use of cross correlation techniques) was applied to the microphone outputs in order to separate the fans’ acoustic emissions from the ambient noise and reflections from the facility walls. A numerical simulation was developed to represent the experimental facility and the measurements. The numerical simulation indicated that the extraneous noise can be satisfactorily separated from the fan noise using the array measurements and post processing the acoustic data with the present DS beamforming technique. (paper)

A CFD Case Study of a Fan Stage with Split Flow Path Subject to Total Pressure Distortion Inflow

Science.gov (United States)

To, Wai-Ming

2017-01-01

This report is the documentation of the work performed under the Hypersonic Project of the NASA's Fundamental Aeronautics Program. It was funded through Task Number NNC10E444T under GESS-2 Contract NNC06BA07B. The objective of the task is to develop advanced computational tools for the simulation of multi-stage turbomachinery in support of aeropropulsion. This includes work elements in extending the TURBO code and validating the multi-stage URANS (Unsteady Reynolds Averaged Navier Stokes) simulation results with the experimental data. The unsteady CFD (Computation Fluid Dynamics) calculations were performed in full wheel mode with and without screen generated total pressure distortion at the computational inflow boundary, as well as in single passage phase lag mode for uniform inflow. The experimental data were provided by NASA from the single stage RTA (Revolutionary Turbine Accelerator) fan test program.Significant non-uniform flow condition at the fan-face of the aeropropulsion system is frequentlyencountered in many of the advanced aerospace vehicles. These propulsion systems can be eithera podded or an embedded design employed in HWB (Hybrid Wing Body) airframe concept. It isalso a topic of interest in military applications, in which advanced air vehicles have already deployedsome form of embedded propulsion systems in their design because of the requirementsof compact and low observable inlets. Even in the conventional airframe/engine design, the fancould operate under such condition when the air vehicle is undergoing rapid maneuvering action.It is believed that a better understanding of the fan’s aerodynamic and aeromechanical responseto this type of operating condition or off design operation would be beneficial to designing distortiontolerant blades for improved engine operability.The objective for this research is to assess the capability of turbomachinery code as an analysistool in understanding the effects and evaluating the impact of flow distortion

Analysis of anchor bolt belongs to fan in nuclear power plant

International Nuclear Information System (INIS)

Miao Xueliang; Luan Xingfeng; Zhang Wei; Bian Chunhua; Yu Xiaoyan; Xu Ke; Liu Hongqun

2014-01-01

Through on the fan anchor bolt material components, metallurgical structure and fracture analysis indicates that: material composition and microscopic are abnormal, it led to material brittle increased, the fracture is rock-candy structure, the last part is toughness structure. The reason is the the fan vibrate oversize. At last, we put forward some measures. Just like, control the vibration of the fan, set a nominal tightening torque when installing bolt. (authors)

Investigation of a double oscillating-fan cooling device using electromagnetic force

International Nuclear Information System (INIS)

Su, Hsien-Chin; Xu, Han Yang

2016-01-01

Highlights: • The characteristics of a double oscillating-fan cooling device using electromagnetic force was investigated. • The driving current can be either DC PWM or AC within 3–12 V. • The comparison between a double blower pair, the model and a synjet were examined. • A 50 mm ∗ 50 mm ∗ 15 mm model can provide the flow rate of 154.89 l/min while consuming 0.65 W. • The flow rate, sound pressure, power consumption and two thermal tests have been done. - Abstract: This study proposes a double oscillating-fan cooling device using electromagnetic force. The device consists of two oscillating-fans. It requires only one electromagnet and two fan sheets with one magnet on each of them. The electromagnet and fan sheets are situated on a base and arranged accordingly. The electromagnetic force generated by the electromagnet can actuate the fan sheets. The main advantage of the device is its simple structure because there is no bearing and motor in the device. The driving current can be either DC PWM (Pulse width modulation) or AC (Alternating current) within 3–12 V so it is compatible with most electronic devices. The dimensions of the proposed model are 50 mm ∗ 50 mm ∗ 15 mm during operation. Concerning flow rate, sound pressure, power consumption and resonant frequency tests, a comparison between the proposed model and different type of cooling devices has been completed. The result shows that the model can provide cooling ability similar to a rotary fan while consuming 40% of the power of the rotary fan. It shows not only a good cooling ability but also a great potential for structural reliability and design flexibility.

30 CFR 57.22208 - Auxiliary fans (I-A, II-A, III, and V-A mines).

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans (I-A, II-A, III, and V-A mines... fans (I-A, II-A, III, and V-A mines). (a) Auxiliary fans, except fans used in shops and other areas... applicable requirements of 30 CFR part 18, and be operated so that recirculation is minimized. Auxiliary fans...

A Field Study of Wall Furnace Venting and Coincident Exhaust Fan Usage in 16 Northern California Apartments

Energy Technology Data Exchange (ETDEWEB)

Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Less, Brennan D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brooks, Andrew [Association for Energy Affordability, Emeryville, CA (United States); Cohn, Sebastian [Association for Energy Affordability, Emeryville, CA (United States); Finn, Brian [Association for Energy Affordability, Emeryville, CA (United States)

2016-09-01

To inform efforts to improve combustion appliance testing in residential energy efficiency programs, we studied the frequency of coincident fan use and depressurization-induced downdrafting and spillage from atmospherically vented (i.e., natural draft) wall furnaces in airtight apartments. Indoor environmental conditions, heating appliance operation, use of exhaust fans, and cooking with stovetop or oven were monitored for approximately three weeks each in 16 apartment units in two buildings in Northern California. Apartments also were assessed using standard combustion appliance safety test methods and enhanced protocols. Monitoring occurred in February and March of 2016, with heating demand corresponding to 7.3 ± 0.5 heating degree-days at a 65ºF reference temperature. Most of the furnaces spilled combustion products when the apartments were depressurized in the “worst-case” challenge condition of all exhaust fans operating at their highest settings and all windows closed. Many also spilled under less challenging conditions (e.g., with kitchen exhaust fan on low and bathroom fan operating). On average, bathroom exhaust fans were operated 3.9% of monitored minutes (13.5% max), and cooking (burner or kitchen fan operation) occurred 4.6% of minutes (max 13.3%). Event lengths averaged 17 minutes (max 540) and 34 minutes (max 324), respectively. Their coincident operation averaged 0.34% of minutes (max 2.0%), with average event length of 13 minutes (max 92 minutes). This suggests that the operation of apartment units at or near the currently used worst-case challenge condition is quite rare. Wall furnace burners operated an average of 2.8% of minutes (max of 8.9%), with average burner cycle length of 14 minutes (max 162). Coincident bath fan use, cooking and wall furnace operation was very rare, occurring only a handful of times across all apartments. The highest rate was 0.075% of monitored minutes in one apartment, and the longest event length was 12 minutes

The media festival volunteer: Connecting online and on-ground fan labor

Directory of Open Access Journals (Sweden)

Robert Moses Peaslee

2014-03-01

Full Text Available n this initial attempt to bring volunteering, or what we call on-ground fan labor, into the ongoing discussion of fan productivity, we examine volunteer motivations as elicited through interview and participant observation data collected at a 2012 genre film festival, Fantastic Fest, held in Austin, Texas. This case study is a first step toward integrating the volunteer and fan labor literatures and interrogating the role of social capital and civic engagement in volunteerism. We conclude that the media festival (a term intended to encompass such sites as film festivals and fan conventions is a site of particular and emergent importance for those studying the audience's increasing delivery of free labor.

Dimensional expansions and shiftings: fan fiction and transmedia storytelling the the Fringeverse

Directory of Open Access Journals (Sweden)

Mar Guerrero-Pico

2016-12-01

Full Text Available This article explores the characteristics of user-generated texts in fictional transmedia storytelling based on the fan fiction originating from FOX’s television series Fringe (2008-2013. A fan fiction (also known as fanfic or fic is a piece of writing in which the author recreates the setting, events and characters of a source text or canon. After reviewing fan theories and practices, the article focuses on three examples examples of Fringe fan fiction analysing them with a double-edged methodology that combines narrative semiotics and narratology. Based on the results we update a set of transmedia narrative strategies by adding dimensional expansion and shifting, and also redefine the different areas of the storyworld where fan fiction is set with special emphasis on alternate universe (AU scenarios.

Global effects of agriculture on fluvial dissolved organic matter

DEFF Research Database (Denmark)

Graeber, Daniel; Boëchat, Iola; Encina, Francisco

2015-01-01

Agricultural land covers approximately 40% of Earth’s land surface and affects hydromorphological, biogeochemical and ecological characteristics of fluvial networks. In the northern temperate region, agriculture also strongly affects the amount and molecular composition of dissolved organic matter...

Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

Science.gov (United States)

Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

2016-01-01

A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

Temperature control of an automotive engine cooling system utilizing a magneto-rheological fan clutch

International Nuclear Information System (INIS)

Kim, Eun-Seok; Choi, Seung-Bok; Park, Young-Gee; Lee, Soojin

2010-01-01

In this note, the temperature control of an automotive engine cooling system is undertaken using a magneto-rheological (MR) fluid-based fan clutch (MR fan clutch in short). In order to achieve this goal, an appropriate size of controllable fan clutch using an MR fluid is firstly devised by considering the design parameters of a conventional fan clutch to reflect the practical application. Then, the principal design parameters of the MR fan clutch such as the length of the disc are optimally determined through finite element analysis. The drum-type MR fan clutch is manufactured and its time response to input current is experimentally evaluated. A robust sliding mode controller is then formulated by treating the time constant of the fan clutch system as an uncertain parameter. After identifying the relationship between angular velocity of the MR fan clutch and the temperature of the cooling system, the sliding mode controller is experimentally realized for the cooling system. It has been clearly demonstrated that the proposed sliding mode controller follows well the desired temperature with a small regulating error. It is expected from this feasibility work that the proposed control system associated with an MR fan clutch can be effectively utilized for the automotive cooling system to improve the fuel efficiency. (technical note)

Effect of a ceiling fan ventilation system on finishing young bulls' health, behaviour and growth performance.

Science.gov (United States)

Magrin, L; Brscic, M; Lora, I; Rumor, C; Tondello, L; Cozzi, G; Gottardo, F

2017-06-01

This research aimed at assessing the effects of a ceiling fan ventilation system on health, feeding, social behaviour and growth response of finishing young bulls fattened indoors during a mild summer season. A total of 69 Charolais young bulls were housed in six pens without any mechanical ventilation system (Control) and in six pens equipped with ceiling fans. The experimental period lasted 98 days from June until mid-September 2014. Four experimental days were considered in order to assess the effect of the ventilation system under two different microclimatic conditions: 2 alert days at monthly interval with temperature humidity index (THI) between 75 and 78, and 2 normal days with THI⩽74. Health and behaviour of the bulls were evaluated through 8-h observation sessions starting after morning feed delivery. The study was carried out during a rather cool summer with a climate average THI of 68.9 and 4 days with average THI>75. Despite these mild climate conditions, ceiling fans lowered litter moisture and acted as a preventive measure for bulls' dirtiness (odd ratio=47.9; 95% CI 19.6 to 117.4). The risk of abnormal breathing was increased for Control bulls (odd ratio=40.7; 95% CI 5.4 to 304.2). When exposed to alert THI conditions, respiration rate and panting scores increased and rumination duration dropped in Control bulls compared with bulls provided with a ceiling fan. During observations under alert THI, bulls spent less time eating, more time being inactive and consumed more water compared with normal THI conditions. Bulls' daily dry matter intake measured during the observation sessions decreased on alert compared with normal THI days (Pbehaviour (rumination, lying down and drinking water) and respiration rate, however. The lack of a significant improvement of bulls' growth response should not discourage beef farmers from using ceiling fans in indoor systems, considering the likely increase in frequency and intensity of heat waves in the planet

Development of high-performance and low-noise axial-flow fan units in their local operating region

Energy Technology Data Exchange (ETDEWEB)

Heo, Seung; Ha, Min Ho; Cheong, Cheol Ung [Pusan National University, Busan (Korea, Republic of); Kim, Tae Hoon [LG Electronics Inc., Changwon (Korea, Republic of)

2015-09-15

Aerodynamic and aeroacoustic performances of an axial-flow fan unit are improved by modifying its housing structure without changing the fan blade. The target axial-flow fan system is used to lower temperature of a compressor and a condenser in the machine room of a household refrigerator which has relatively high system resistance due to complex layout of structures inside it. First, the performance of the fan system is experimentally characterized by measuring its volume flow rate versus static pressure using a fan performance tester satisfying the AMCA (Air Movement and Control Association) regulation, AMCA 210-07. The detailed structure of flow driven by the fan is numerically investigated using a virtual fan performance tester based on computational fluid dynamics techniques. The prediction result reveals possible loss due to radial and tangential velocity components in the wake flow downstream of the fan. The length of the fan housing is chosen as a design parameter for improving the aerodynamic and aeroacoustic performances of the fan unit by reducing the identified radial and tangential velocity components. Three fan units with different housing lengths longer than the original are analyzed using the virtual fan performance tester. The results confirm the improved aerodynamic performance of the proposed three designs. The flow field driven by the proposed fan unit is closely examined to find the causes for the observed performance improvements, which ensures that the radial and tangential velocity components in the wake flow are reduced. Finally, the improved performance of the proposed fan systems is validated by comparing the P-Q and efficiency curves measured using the fan performance tester. The noise emission from the household refrigerator is also found to be lessened when the new fan units are installed.

Energy-Saving Performance of Flap-Adjustment-Based Centrifugal Fan

Directory of Open Access Journals (Sweden)

Genglin Chen

2018-01-01

Full Text Available The current paper mainly focuses on finding a more appropriate way to enhance the fan performance at off-design conditions. The centrifugal fan (CF based on flap-adjustment (FA has been investigated through theoretical, experimental, and finite element methods. To obtain a more predominant performance of CF from the different adjustments, we carried out a comparative analysis on FA and leading-adjustment (LA in aerodynamic performances, which included the adjusted angle of blades, total pressure, efficiency, system-efficiency, adjustment-efficiency, and energy-saving rate. The contribution of this paper is the integrated performance curve of the CF. Finally, the results showed that the effects of FA and LA on economic performance and energy savings of the fan varied with the blade angles. Furthermore, FA was feasible, which is more sensitive than LA. Moreover, the CF with FA offered a more extended flow-range of high economic characteristic in comparison with LA. Finally, when the operation flow-range extends, energy-saving rate of the fan with FA would have improvement.

Fluvial processes on Mars: Erosion and sedimentation

Science.gov (United States)

Squyres, Steven W.

1988-01-01

One of the most important discoveries of the Mariner 9 and Viking missions to Mars was evidence of change of the Martian surface by the action of liquid water. From the standpoint of a Mars Rover/Sample Return Mission, fluvial activity on Mars is important in two ways: (1) channel formation has deeply eroded the Martian crust, providing access to relatively undisturbed subsurface units; and (2) much of the material eroded from channels may have been deposited in standing bodies of liquid water. The most striking fluvial erosion features on Mars are the outflow channels. A second type of channel apparently caused by flow of liquid water is the valley systems. These are similar to terrestial drainage systems. The sedimentary deposits of outflow channels are often difficult to identfy. No obvious deposits such as deltaic accumulations are visible in Viking images. Another set of deposits that may be water lain and that date approx. from the epoch of outflow channels are the layered deposits in the Valles Marineris. From the standpoint of a Mars Rover/Sample Return mission, the problem with all of these water-lain sediments is their age, or rather the lack of it.

Numerical investigation of geometric parameter effects on the aerodynamic performance of a Bladeless fan

OpenAIRE

Mohammad Jafari; Hossein Afshin; Bijan Farhanieh; Atta Sojoudi

2016-01-01

Aerodynamic performance of a Bladeless fan is numerically investigated considering the effect of five geometric parameters. Airflow through this fan was analyzed by simulating a Bladeless fan within a 2 m × 2 m × 4 m room. Analysis of the flow field inside the fan and the evaluation of its performance were obtained by solving conservations of mass and momentum equations for the aerodynamic investigations. In order to design the Bladeless fan an Eppler 473 airfoil profile was used as the cross...

Creative choices and fan practices in the transformation of theme park space

Directory of Open Access Journals (Sweden)

Carissa Ann Baker

2016-09-01

Full Text Available This article describes and interprets fan activities within the theme park space related to a particular fan object. It examines an evolving paradigm wherein the role of theme park visitors is changed. Rather than being perceived as observers of spectacles, they can participate and interact with the environment in new ways. An example of this is Sorcerers of the Magic Kingdom (2012, an interactive role-playing quest and collector card game at Disney's Magic Kingdom Park in Florida. Fans participate in a variety of practices that have dynamically redefined theme park activities. Together, management, designers, and fans have cocreated and reconstructed the theme park experience as one of exploration and participation. Despite multiple levels of control, fans will likewise persist in engagement with activities (in park and online that help shape and interrogate the theme park space.

Football fan aggression: the importance of low Basal cortisol and a fair referee.

Directory of Open Access Journals (Sweden)

Leander van der Meij

Full Text Available Fan aggression in football (soccer is a societal problem that affects many countries worldwide. However, to date, most studies use an epidemiological or survey approach to explain football fan aggression. This study used a controlled laboratory study to advance a model of predictors for fan aggression. To do so, football fans (n = 74 saw a match summary in which their favorite team lost against their most important rival. Next, we measured levels of aggression with the hot sauce paradigm, in which fans were given the opportunity to administer a sample of hot sauce that a rival football supporter had to consume. To investigate if media exposure had the ability to reduce aggression, before the match fans saw a video in which fans of the rival team commented in a neutral, negative, or positive manner on their favorite team. Results showed that the media exposure did not affect aggression. However, participants displayed high levels of aggression and anger after having watched the match. Also, aggression was higher in fans with lower basal cortisol levels, which suggests that part of the aggression displayed was proactive and related to anti-social behavior. Furthermore, aggression was higher when the referee was blamed and aggression was lower when the performance of the participants' favorite team was blamed for the match result. These results indicate that aggression increased when the match result was perceived as unfair. Interventions that aim to reduce football fan aggression should give special attention to the perceived fairness of the match result.

INFLUENCE OF APPLYING ADDITIONAL FORCING FANS FOR THE AIR DISTRIBUTION IN VENTILATION NETWORK

Directory of Open Access Journals (Sweden)

Nikodem SZLĄZAK

2016-07-01

Full Text Available Mining progress in underground mines cause the ongoing movement of working areas. Consequently, it becomes neces-sary to adapt the ventilation network of a mine to direct airflow into newly-opened districts. For economic reasons, opening new fields is often achieved via underground workings. Length of primary intake and return routes increases and also increases the total resistance of a complex ventilation network. The development of a subsurface structure can make it necessary to change the air distribution in a ventilation network. Increasing airflow into newly-opened districts is necessary. In mines where extraction does not entail gas-related hazards, there is possibility of implementing a push-pull ventilation system in order to supplement airflows to newly developed mining fields. This is achieved by installing sub-surface fan stations with forcing fans at the bottom of downcast shaft. In push-pull systems with multiple main fans, it is vital to select forcing fans with characteristic curves matching those of the existing exhaust fans to prevent undesirable mutual interaction. In complex ventilation networks it is necessary to calculate distribution of airflow (especially in net-works with a large number of installed fans. In the article the influence of applying additional forcing fans for the air distribution in ventilation network for underground mine were considered. There are also analysed the extent of over-pressure caused by the additional forcing fan in branches of the ventilation network (the operating range of additional forcing fan. Possibilities of increasing airflow rate in working areas were conducted.

Football Fan Aggression: The Importance of Low Basal Cortisol and a Fair Referee

Science.gov (United States)

van der Meij, Leander; Almela, Mercedes; van Lange, Paul A. M.

2015-01-01

Fan aggression in football (soccer) is a societal problem that affects many countries worldwide. However, to date, most studies use an epidemiological or survey approach to explain football fan aggression. This study used a controlled laboratory study to advance a model of predictors for fan aggression. To do so, football fans (n = 74) saw a match summary in which their favorite team lost against their most important rival. Next, we measured levels of aggression with the hot sauce paradigm, in which fans were given the opportunity to administer a sample of hot sauce that a rival football supporter had to consume. To investigate if media exposure had the ability to reduce aggression, before the match fans saw a video in which fans of the rival team commented in a neutral, negative, or positive manner on their favorite team. Results showed that the media exposure did not affect aggression. However, participants displayed high levels of aggression and anger after having watched the match. Also, aggression was higher in fans with lower basal cortisol levels, which suggests that part of the aggression displayed was proactive and related to anti-social behavior. Furthermore, aggression was higher when the referee was blamed and aggression was lower when the performance of the participants’ favorite team was blamed for the match result. These results indicate that aggression increased when the match result was perceived as unfair. Interventions that aim to reduce football fan aggression should give special attention to the perceived fairness of the match result. PMID:25844939

Pathological effects of cyanobacteria on sea fans in southeast Florida.

Science.gov (United States)

Kiryu, Y; Landsberg, J H; Peters, E C; Tichenor, E; Burleson, C; Perry, N

2015-07-01

In early August 2008, observations by divers indicated that sea fans, particularly Gorgonia ventalina, Gorgonia flabellum, and Iciligorgia schrammi, were being covered by benthic filamentous cyanobacteria. From August 2008 through January 2009 and again in April 2009, tissue samples from a targeted G. ventalina colony affected by cyanobacteria and from a nearby, apparently healthy (without cyanobacteria) control colony, were collected monthly for histopathological examination. The primary cellular response of the sea fan to overgrowth by cyanobacteria was an increase in the number of acidophilic amoebocytes (with their granular contents dispersed) that were scattered throughout the coenenchyme tissue. Necrosis of scleroblasts and zooxanthellae and infiltration of degranulated amoebocytes were observed in the sea fan surface tissues at sites overgrown with cyanobacteria. Fungal hyphae in the axial skeleton were qualitatively more prominent in cyanobacteria-affected sea fans than in controls. Copyright © 2015 Elsevier Inc. All rights reserved.

Female fans of men's football - a case study in Denmark

DEFF Research Database (Denmark)

Pfister, Gertrud Ursula; Lenneis, Verena; Mintert, Svenja-Maria

2013-01-01

Football is an invention by men for men, and today, the majority of players and fans are men. There is an abundance of literature on football and fandom; however, gender is mostly not an issue in these publications. Research about female football supporters and fans is very limited. This is also...... true for Denmark, the country, which is the focus of this article. Based on gender and socialization theories, this contribution addresses women and their (lack of) interest in men's football. The main questions refer to the numbers of female supporters and their patterns of football consumption...... to a 'man's world' and what are their roles in this 'male environment'? The statements of interviewees revealed that female fans have to cope with a measure of sexism, but that they can adopt the men's perspectives in order to be accepted as 'authentic fans'. Other women reacted on men's domination...

Fluvial geomorphology: where do we go from here?

Science.gov (United States)

Smith, Derald G.

1993-07-01

The evolution of geomorphology and in particular, fluvial geomorphology, is at a crossroads. Currently, the discipline is dismally organized, without focus or direction, and is practised by individualists who rarely collaborate in numbers significant enough to generate major research initiatives. If the discipline is to mature and to prosper, we must make some very difficult decisions that will require major changes in our ways of thinking and operating. Either the field stays in its current operational mode and becomes a backwater science, or it moves forward and adopts the ways of the more competitive sectors of the earth and biosciences. For the discipline to evolve, fluvial geomorphologists must first organize an association within North America or at the international level. The 3rd International Geomorphology Conference may be a start, but within that organization we must develop our own divisional and/or regional organizations. Within the Quaternary geology/geomorphology divisions of the Geological Socieity of America (GSA), Association of American Geographers (AAG), American Geophysical Union (AGU) and British Geomorphology Research Group (BGRG) the voice of fluvial geomorphology is lost in a sea of diverse and competitive interests, though there is reason for hope resulting from some recent initiatives. In Canada, we have no national geomorphology organization per se; our closest organization is Canqua (Canadian Quaternary Association). Next, fluvial researchers must collaborate, by whatever means, to develop "scientific critical mass" in order to generate ideas and long-range goals of modest and major scientific importance. These projects will help secure major research funding without which, research opportunities will diminish and initiating major new research will become nearly impossible. Currently, we are being surpassed by the glaciologists, remote sensors, ecologists, oceanographers, climatologists-atmospheric researchers and some Quaternary

Laser Displacement Measurements of Fan Blades in Resonance and Flutter During the Boundary Layer Ingesting Inlet and Distortion-Tolerant Fan Test

Science.gov (United States)

Duffy, Kirsten P.; Provenza, Andrew J.; Bakhle, Milind A.; Min, James B.; Abdul-Aziz, Ali

2018-01-01

NASA's Advanced Air Transport Technology Project is investigating boundary layer ingesting propulsors for future subsonic commercial aircraft to improve aircraft efficiency, thereby reducing fuel burn. To that end, a boundary layer ingesting inlet and distortion-tolerant fan stage was designed, fabricated, and tested within the 8' x 6' Supersonic Wind Tunnel at NASA Glenn Research Center. Because of the distortion in the air flow over the fan, the blades were designed to withstand a much higher aerodynamic forcing than for a typical clean flow. The blade response for several resonance modes were measured during start-up and shutdown, as well as at near 85% design speed. Flutter in the first bending mode was also observed in the fan at the design speed, at an off-design condition, although instabilities were difficult to instigate with this fan in general. Blade vibrations were monitored through twelve laser displacement probes that were placed around the inner circumference of the casing, at the blade leading and trailing edges. These probes captured the movement of all the blades during the entire test. Results are presented for various resonance mode amplitudes, frequencies and damping, as well as flutter amplitudes and frequency. Benefits and disadvantages of laser displacement probe measurements versus strain gage measurements are discussed.

Shaking table test study on seismic performance of dehydrogenation fan for nuclear power plants

International Nuclear Information System (INIS)

Liu Kaiyan; Shi Weixing; Cao Jialiang; Wang Yang

2011-01-01

Seismic performance of the dehydrogenation fan for nuclear power plants was evaluated based on the shaking table test of earthquake simulation. Dynamic characteristics including the orthogonal tri-axial fundamental frequencies and equivalent damping ratios were measured by the white noise scanning method. Artificial seismic waves were generated corresponding to the floor acceleration response spectra for nuclear power plants. Furthermore, five OBE and one SSE shaking table tests for dehydrogenation fan were performed by using the artificial seismic waves as the seismic inputs along the orthogonal axis simultaneity. Operating function of dehydrogenation fan was monitored and observed during all seismic tests, and performance indexes of dehydrogenation fan were compared before and after seismic tests. The results show that the structural integrity and operating function of the dehydrogenation fan are perfect during all seismic tests; and the performance indexes of the dehydrogenation fan can remain consistent before and after seismic tests; the seismic performance of the dehydrogenation fan can satisfy relevant technical requirements. (authors)

Design and Testing of Braided Composite Fan Case Materials and Components

Science.gov (United States)

Roberts, Gary D.; Pereira, J. Michael; Braley, Michael S.; Arnold, William a.; Dorer, James D.; Watson, William R/.

2009-01-01

Triaxial braid composite materials are beginning to be used in fan cases for commercial gas turbine engines. The primary benefit for the use of composite materials is reduced weight and the associated reduction in fuel consumption. However, there are also cost benefits in some applications. This paper presents a description of the braided composite materials and discusses aspects of the braiding process that can be utilized for efficient fabrication of composite cases. The paper also presents an approach that was developed for evaluating the braided composite materials and composite fan cases in a ballistic impact laboratory. Impact of composite panels with a soft projectile is used for materials evaluation. Impact of composite fan cases with fan blades or blade-like projectiles is used to evaluate containment capability. A post-impact structural load test is used to evaluate the capability of the impacted fan case to survive dynamic loads during engine spool down. Validation of these new test methods is demonstrated by comparison with results of engine blade-out tests.

Optimized Matching Lift Unit Transmission Ratio of Engine Driven Ducted Fan

Directory of Open Access Journals (Sweden)

Xiao Senlin

2018-01-01

Full Text Available As a kind of VTOL technology, ducted fan is not only used by many kinds of aircrafts, but also one of the trends of the future aircraft lift system, and attracts more and more attention. For an engine driven ducted fan lift unit, involving the engine and ducted fan matching problem, the form of transmission and transmission ratio are the key design parameters. In order to design and develop a ducted fan aircraft reasonably, a thrust test platform was set up to connect the engine with the ducted fan through the belt driving. The matching relationship between the engine and the transmission system was experimentally studied and the optimal transmission ratio was determined. The results showed that the optimal transmission ratio for the engine 1 is 2.2:1, and for the engine 2, the optimal transmission ratio should be 2.95:1 based on the current ducted and movable blade aerofoil design. At this time, the lift will exceed 130 kg•f, meeting the aircraft's original design requirements.

Design of flood protection for transportation alignments on alluvial fans

International Nuclear Information System (INIS)

French, R.H.

1991-01-01

The method of floodplain delineation on alluvial fans developed for the national flood insurance program is modified to provide estimates of peak flood flows at transportation alignments crossing an alluvial fan. The modified methodology divides the total alignment length into drainage design segments and estimates the peak flows that drainage structures would be required to convey as a function of the length of the drainage design segment, the return period of the event, and the location of the alignment on the alluvial fan. An example of the application of the methodology is provided. 16 refs., 5 figs

Numerical investigation of geometric parameter effects on the aerodynamic performance of a Bladeless fan

Directory of Open Access Journals (Sweden)

Mohammad Jafari

2016-03-01

Full Text Available Aerodynamic performance of a Bladeless fan is numerically investigated considering the effect of five geometric parameters. Airflow through this fan was analyzed by simulating a Bladeless fan within a 2 m × 2 m × 4 m room. Analysis of the flow field inside the fan and the evaluation of its performance were obtained by solving conservations of mass and momentum equations for the aerodynamic investigations. In order to design the Bladeless fan an Eppler 473 airfoil profile was used as the cross section of the fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter, and aspect ratio for circular and quadratic cross sections were considered. Validating 3-D numerical results, experimental results of a round jet showed good agreement with those of the simulation data. The multiplier factor M is defined to show the ratio of the outlet flow rate to inlet flow rate from the fan. The obtained numerical results showed that the Discharge ratio has the maximum value for the height of 3 cm. The numerical outcomes of outlet thickness variation indicate that this parameter is one of the most influential parameters on the aerodynamic performance of a Bladeless fan. The results for the outlet thicknesses of 1, 2 and 3 mm showed that the Discharge ratio increased significantly when the outlet thickness decreased.

Broadband Fan Noise Prediction System for Turbofan Engines. Volume 3; Validation and Test Cases

Science.gov (United States)

Morin, Bruce L.

2010-01-01

Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the third volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User s Manual and Developer s Guide; Volume 2: BFaNS User s Manual and Developer s Guide; and Volume 3: Validation and Test Cases. The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by validation studies that were done on three fan rigs. It concludes with recommended improvements and additional studies for BFaNS.

Fluvial archives, a valuable record of vertical crustal deformation

Science.gov (United States)

Demoulin, A.; Mather, A.; Whittaker, A.

2017-06-01

The study of drainage network response to uplift is important not only for understanding river system dynamics and associated channel properties and fluvial landforms, but also for identifying the nature of crustal deformation and its history. In recent decades, geomorphic analysis of rivers has proved powerful in elucidating the tectonic evolution of actively uplifting and eroding orogens. Here, we review the main recent developments that have improved and expanded qualitative and quantitative information about vertical tectonic motions (the effects of horizontal deformation are not addressed). Channel long profiles have received considerable attention in the literature, and we briefly introduce basic aspects of the behaviour of bedrock rivers from field and numerical modelling perspectives, before describing the various metrics that have been proposed to identify the information on crustal deformation contained within their steady-state characteristics. Then, we review the literature dealing with the transient response of rivers to tectonic perturbation, through the production of knickpoints propagating through the drainage network. Inverse modelling of river profiles for uplift in time and space is also shown to be very effective in reconstructing regional tectonic histories. Finally, we present a synthetic morphometric approach for deducing the tectonic record of fluvial landscapes. As well as the erosional imprint of tectonic forcing, sedimentary deposits, such as fluvial terrace staircases, are also considered as a classical component of tectonic geomorphology. We show that these studies have recently benefited from rapid advances in dating techniques, allowing more reliable reconstruction of incision histories and estimation of incision rates. The combination of progress in the understanding of transient river profiles and larger, more rigorous data sets of terrace ages has led to improved understanding of river erosion and the implications for terrace

Applicability of fan spray nozzles to stripping insoluble gases from viscous liquids

International Nuclear Information System (INIS)

Tseng, H.H.; Johnson, E.F.

1983-08-01

Fan spray nozzle stripping appears to be a practical technique for separating dilute volatile solutes from nonvolatile solvents. In particular this technique can be used to strip molecular tritium and tritium fluoride at extremely small concentration (in the parts per million range) from molten salts used as blanket materials in a fusion reactor. Under adjusted operating conditions of the fan spray as it leaves the nozzle, a high percentage of the theoretically maximum achievable stripping would take place from the expanding sheet of the fan spray as it leaves the nozzle and before it breaks up. Although the only available experimental data are for aqueous solutions, a new theoretical analysis of the fan spray sheet demonstrates the applicability of this technique to nonaqueous liquids. The equation derived from this analysis relates the theoretically achievable mass transfer efficiency to the properties of the liquid flowing through the fan spray nozzle and to the operating conditions of the nozzle. Any fluid with viscosity higher than or equal to that of water would be expected to follow this equation as long as a fan-shaped sheet is formed under the operating conditions of the nozzle

Influence of fluvial sandstone architecture on geothermal energy production

NARCIS (Netherlands)

Willems, C.J.L.; Maghami Nick, Hamidreza M.; Weltje, G.J.; Donselaar, M.E.; Bruhn, D.F.

2015-01-01

Fluvial sandstone reservoirs composed of stacked meander belts are considered as potential geothermal resources in the Netherlands. Net-to-gross, orientation and stacking pattern of the channel belts is of major importance for the connectivity between the injection and production well in such

Reservoirs as hotspots of fluvial carbon cycling in peatland catchments.

Science.gov (United States)

Stimson, A G; Allott, T E H; Boult, S; Evans, M G

2017-02-15

Inland water bodies are recognised as dynamic sites of carbon processing, and lakes and reservoirs draining peatland soils are particularly important, due to the potential for high carbon inputs combined with long water residence times. A carbon budget is presented here for a water supply reservoir (catchment area~9km 2 ) draining an area of heavily eroded upland peat in the South Pennines, UK. It encompasses a two year dataset and quantifies reservoir dissolved organic carbon (DOC), particulate organic carbon (POC) and aqueous carbon dioxide (CO 2 (aq)) inputs and outputs. The budget shows the reservoir to be a hotspot of fluvial carbon cycling, as with high levels of POC influx it acts as a net sink of fluvial carbon and has the potential for significant gaseous carbon export. The reservoir alternates between acting as a producer and consumer of DOC (a pattern linked to rainfall and temperature) which provides evidence for transformations between different carbon species. In particular, the budget data accompanied by 14 C (radiocarbon) analyses provide evidence that POC-DOC transformations are a key process, occurring at rates which could represent at least ~10% of the fluvial carbon sink. To enable informed catchment management further research is needed to produce carbon cycle models more applicable to these environments, and on the implications of high POC levels for DOC composition. Copyright © 2016 Elsevier B.V. All rights reserved.

Preliminary Geological Map of the Peace Vallis Fan Integrated with In Situ Mosaics From the Curiosity Rover, Gale Crater, Mars

Science.gov (United States)

Sumner, D. Y.; Palucis, M.; Dietrich, B.; Calef, F.; Stack, K. M.; Ehlmann, B.; Bridges, J.; Dromart, J.; Eigenbrode, J.; Farmer, J.;

The Retarding Force on a Fan-Cart Reversing Direction

Science.gov (United States)

Aurora, Tarlok S.; Brunner, Bernard J.

2011-01-01

In introductory physics, students learn that an object tossed upward has a constant downward acceleration while going up, at the highest point and while falling down. To demonstrate this concept, a self-propelled fan cart system is used on a frictionless track. A quick push is given to the fan cart and it is allowed to move away on a track under…

Violent fan fluctuations: a diffusion perspective to explain supporters' violence

NARCIS (Netherlands)

Braun, R.; Vliegenthart, R.

2009-01-01

In this article, we address the question of how diffusion mechanisms predict the level of violence among soccer fans. We embed possible causes of violent fan behavior in a theoretical framework of diffusion, as social movement scholars deploy it to study other instances of collective violence. Four

Historicizing video game series through fan art discourses

Directory of Open Access Journals (Sweden)

Jan Švelch

2016-09-01

Full Text Available In this article, we argue that fannish histories should not be dismissed as mere nostalgia over past experiences of one's own media fandom. Instead they should be understood as complex narratives which combine various historical layers (personal, productional, fictional and influence the future reception of and anticipation for sequels. They also shed light on the personal histories of fans, which are often juxtaposed with extratextual and fictional histories of a video game series. The subjective nature of these historical discourses is not to be seen as a constraint but as a feature of everyday history which points to the prominence of historicizing in fan cultures of video game series. These topics are examined in the selected multimodal material from the site DeviantArt consisting of fan art pieces, authorial captions, and respective comments inspired by two single-player video game series: Tomb Raider and Mass Effect.

The Forming of AISI 409 sheets for fan blade manufacturing

International Nuclear Information System (INIS)

Foroni, F. D.; Menezes, M. A.; Moreira Filho, L. A.

2007-01-01

The necessity of adapting the standardized fan models to conditions of higher temperature has emerged due to the growth of concern referring to the consequences of the gas expelling after the Mont Blanc tunnel accident in Italy and France, where even though, with 100 fans in operation, 41 people died. The objective of this work is to present an alternative to the market standard fans considering a new technology in constructing blades. This new technology introduces the use of the stainless steel AISI 409 due to its good to temperatures of gas exhaust from tunnels in fire situation. The innovation is centered in the process of a deep drawing of metallic sheets in order to keep the ideal aerodynamic superficies for the fan ideal performance. Through the impression of circles on the sheet plane it is shown, experimentally, that, during the pressing process, the more deformed regions on the sheet plane of the blade can not reach the deformation limits of the utilized sheet material

Numerical Simulation of Boundary Layer Ingesting (BLI) Inlet-Fan Interaction

Science.gov (United States)

Giuliani, James; Chen, Jen-Ping; Beach, Timothy; Bakhle, Milind

2014-01-01

Future civil transport designs may incorporate engine inlets integrated into the body of the aircraft to take advantage of efficiency increases due to weight and drag reduction. Additional increases in engine efficiency are predicted if the inlet ingests the lower momentum boundary layer flow. Previous studies have shown, however, that efficiency benefits of Boundary Layer Ingesting (BLI) ingestion are very sensitive to the magnitude of fan and duct losses, and blade structural response to the non-uniform flow field that results from a BLI inlet has not been studied in-depth. This paper presents an effort to extend the modeling capabilities of an existing rotating turbomachinery unsteady analysis code to include the ability to solve the external and internal flow fields of a BLI inlet. The TURBO code has been a successful tool in evaluating fan response to flow distortions for traditional engine/inlet integrations, such as the development of rotating stall and inlet distortion through compressor stages. This paper describes the first phase of an effort to extend the TURBO model to calculate the external and inlet flowfield upstream of fan so that accurate pressure distortions that result from BLI configurations can be computed and used to analyze fan aerodynamics and structural response. To validate the TURBO program modifications for the BLI flowfield, experimental test data obtained by NASA for a flushmounted S-duct with large amounts of boundary layer ingestion was modeled. Results for the flow upstream and in the inlet are presented and compared to experimental data for several high Reynolds number flows to validate the modifications to the solver. Quantitative data is presented that indicates good predictive capability of the model in the upstream flow. A representative fan is attached to the inlet and results are presented for the coupled inlet/fan model. The impact on the total pressure distortion at the AIP after the fan is attached is examined.

Variability in fluvial geomorphic response to anthropogenic disturbance

Science.gov (United States)

Verstraeten, Gert; Broothaerts, Nils; Van Loo, Maarten; Notebaert, Bastiaan; D'Haen, Koen; Dusar, Bert; De Brue, Hanne

2017-10-01

Humans have greatly impacted the processes and intensities of erosion, sediment transport and storage since the introduction of agriculture. In many regions around the world, accelerated floodplain sedimentation can be related to increases in human pressure on the environment. However, the relation between the intensity of anthropogenic disturbance and the magnitude of change in fluvial sediment dynamics is not straightforward and often non-linear. Here, we review a number of case studies from contrasting environmental settings in the European loess belt, the Eastern Mediterranean mountain ranges and the eastern USA. Detailed field-based sediment archive studies and sediment budgets covering time periods ranging from 200 to over 5000 year, as well as the use of pollen and sediment provenance techniques, show that no overarching concept of changes in floodplain sedimentation following anthropogenic disturbance can be established. Slope-channel (dis)connectivity controls the existence of thresholds or tipping points that need to be crossed before significant changes in downstream sediment dynamics are recorded following human impact. This coupling can be related to characteristics of human pressure such as its duration, intensity and spatial patterns, but also to the geomorphic and tectonic setting. Furthermore, internal feedback mechanisms, such as those between erosion and soil thickness, further complicate the story. All these factors controlling the propagation of sediment from eroding hillslopes to river channels vary between regions. Hence, only unique patterns of fluvial geomorphic response can be identified. As a result, unravelling the human impact from current-day sediment archives and predicting the impact of future human disturbances on fluvial sediment dynamics remain a major challenge. This has important implications for interpreting contemporary sediment yields as well as downstream sediment records in large floodplains, deltas and the marine

SISTEMA FLUVIAL E PLANEJAMENTO LOCAL NO SEMIÁRIDO

Directory of Open Access Journals (Sweden)

Jonas Otaviano Praça de Souza

2012-01-01

Full Text Available El presente estudio analiza un sistema fluvial semiárido y sus características físicas, centrándose en los procesos geomorfológicos y las formas resultantes, sino también en las relaciones con las actividades humanas, con el fin de utilizar dichos datos en la planificación local. La encuesta se llevó a cabo en el municipio de Belém do São Francisco, en Pernambuco, mesorregión del São Francisco en la cuenca del arroyo Mulungu, lugar expuesto a un clima semi-árido con lluvias de verano, y la cobertura del suelo con un predominio de la caatinga arbustiva abierta. Se tomó como procedimiento metodológico la cartografía geomorfológica a diferentes escalas y con diferentes énfasis, para evaluar la relación jerárquica entre los distintos compartimentos, sustratos geológicos y formas de uso de la tierra. De la información espacial obtenida en los distintos niveles de la cartografía detallada del sistema fluvial, se realizó una evaluación ambiental de la zona, teniendo como base la dinámica erosiva/deposicional a lo largo del canal y su relación con sus bancos. Se concluyó que las formas de acumulación en la llanura aluvial exhiben controles de origen antropogénico, vinculados a los tipos tradicionales de uso del suelo en la cuenca. Estos controles, como la construcción de represas a lo largo del canal, actúan cambiando a los procesos de creación de nuevas morfologías de depósito en el sistema fluvial, que a su vez comienzan a redefinir los tipos usos de la zona.

Sport fans' impressions of gay male athletes.

Science.gov (United States)

Campbell, Jamonn; Cothren, Denise; Rogers, Ross; Kistler, Lindsay; Osowski, Anne; Greenauer, Nathan; End, Christian

2011-01-01

The purpose of this study was to examine sport fans' impressions of gay male athletes. Participants formed impressions of a fictional athlete from their favorite team after reading a short scenario about the player. The scenarios described the athlete as being gay or straight, and either becoming a distraction or not causing a distraction to the team. While males' ratings of the athlete did not significantly differ, female fans formed significantly more positive impressions of the gay male player than the straight athlete. These results are discussed in terms of the ingroup bias and the shifting culture of homophobia in sport.

Combined fluvial and pluvial urban flood hazard analysis: method development and application to Can Tho City, Mekong Delta, Vietnam

Science.gov (United States)

Apel, H.; Trepat, O. M.; Hung, N. N.; Chinh, D. T.; Merz, B.; Dung, N. V.

2015-08-01

Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas, and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either fluvial or pluvial flood hazard, studies of combined fluvial and pluvial flood hazard are hardly available. Thus this study aims at the analysis of fluvial and pluvial flood hazard individually, but also at developing a method for the analysis of combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as example. In this tropical environment the annual monsoon triggered floods of the Mekong River can coincide with heavy local convective precipitation events causing both fluvial and pluvial flooding at the same time. Fluvial flood hazard was estimated with a copula based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. Pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data, and a stochastic rain storm generator. Inundation was simulated by a 2-dimensional hydrodynamic model implemented on a Graphical Processor Unit (GPU) for time-efficient flood propagation modelling. All hazards - fluvial, pluvial and combined - were accompanied by an uncertainty estimation considering the natural variability of the flood events. This resulted in probabilistic flood hazard maps showing the maximum inundation depths for a selected set of probabilities of occurrence, with maps showing the expectation (median) and the uncertainty by

On passion and sports fans: a look at football.

Science.gov (United States)

Vallerand, Robert J; Ntoumanis, Nikos; Philippe, Frederick L; Lavigne, Geneviève L; Carbonneau, Noémie; Bonneville, Arielle; Lagacé-Labonté, Camille; Maliha, Gabrielle

2008-10-01

The purpose of the present research was to test the applicability of the Dualistic Model of Passion (Vallerand et al., 2003) to being a sport (football) fan. Three studies provided support for this dualistic conceptualization of passion. Study 1 showed that harmonious passion was positively associated with adaptive behaviours (e.g. celebrate the team's victory), whereas obsessive passion was positively associated with maladaptive behaviours (e.g. risking losing one's job to go to a game). Study 2 used a short Passion Scale and showed that harmonious passion was positively related to the positive affective life of fans during the 2006 FIFA World Cup, psychological health (self-esteem and life satisfaction), and public displays of adaptive behaviours (e.g. celebrate the team's victory into the streets), whereas obsessive passion was predictive of maladaptive affective life (e.g. hating opposing teams' fans) and behaviours (e.g. mocking opposing teams' fans). Finally, Study 3 examined the role of obsessive passion as a predictor of partner's conflict that in turn undermined partner's relationship satisfaction. Overall, the present results provided support for the Dualistic Model of Passion. The conceptual and applied implications of the findings are discussed.

Calculation of forces on reactor containment fan cooler piping

International Nuclear Information System (INIS)

Miller, J.S.; Ramsden, K.

2004-01-01

The purpose of this paper is to present the results of the Reactor Containment Fan Cooler (RCFC) system piping load calculations. These calculations are based on piping loads calculated using the EPRI methodology and RELAP5 to simulate the hydraulic behavior of the system. The RELAP5 generated loads were compared to loads calculated using the EPRI GL-96-06 methodology. This evaluation was based on a pressurized water reactor's RCFC coils thermal hydraulic behavior during a Loss of Offsite Power (LOOP) and a loss of coolant accident (LOCA). The RCFC consist of two banks of service water and chill water coils. There are 5 SX and 5 chill water coils per bank. Therefore, there are 4 RCFC units in the containment with 2 banks of coils per RCFC. Two Service water pumps provide coolant for the 4 RCFC units (8 banks total, 2 banks per RCFC unit and 2 RCFC units per pump). Following a LOOP/LOCA condition, the RCFC fans would coast down and upon being re-energized, would shift to low-speed operation. The fan coast down is anticipated to occur very rapidly due to the closure of the exhaust damper as a result of LOCA pressurization effects. The service water flow would also coast down and be restarted in approximately 43 seconds after the initiation of the event. The service water would drain from the RCFC coils during the pump shutdown and once the pumps restart, water is quickly forced into the RCFC coils causing hydraulic loading on the piping. Because of this scenario and the potential for over stressing the piping, an evaluation was performed by the utility using RELAP5 to assess the piping loads. Subsequent to the hydraulic loads being analyzed using RELAP5, EPRI through GL-96-06 provided another methodology to assess loads on the RCFC piping system. This paper presents the results of using the EPRI methodology and RELAP5 to perform thermal hydraulic load calculations. It is shown that both EPRI methodology and RELAP5 calculations can be used to generate hydraulic loads

Stable isotope study of ground water recharge and movement in the Shogawa Fan, Toyama

International Nuclear Information System (INIS)

Mizutani, Yoshihiko; Oda, Matsuhisa

1983-01-01

Deuterium and oxygen-18 measurements of ground and river waters of the Shogawa Fan, Toyama, have been used to identify sources of water in aquifers in the Fan. A significant difference exists in deltaD and delta 18 O values between two major rivers flowing onto the Fan. On the basis of this difference, it is indicated that aquifers in the eastern half of the Fan are recharged from the Sho River and those in the western half of the Fan are from the Oyabe River. Chloride measurements of the waters support this identification of water sources. Contributions of other water sources to the aquifers are also indicated. The flow rate of infiltration from the Sho River is estimated to be 10-13 m/day in the confined aquifers in the northern part of the Fan. (author)

Performance power evaluation of DC fan cooling system for PV panel by using ANSYS CFX

Science.gov (United States)

Syafiqah, Z.; Amin, N. A. M.; Irwan, Y. M.; Irwanto, M.; Leow, W. Z.; Amelia, A. R.

2017-09-01

A research has been conducted to find the optimum combination for DC fan air cooling system of photovoltaic (PV) panel. During normal operation of PV panel, it is estimated that only 15 % of solar radiation is converted into electrical energy. Meanwhile, the rest of the solar radiation is converted into heat energy which affects the performance of the PV panel. Therefore, the aim of this research is to investigate the performance power evaluation of DC fan cooling system for PV panel by using ANSYS CFX. The effect of airflow configuration of DC fan has been investigated. This is to analyze whether the airflow circulation of DC fan cause a change towards the maximum temperature of PV panel. Besides, the impact of varying number of DC fans attached at the back of PV panel is evaluated. The result of airflow circulation of DC fan has been discussed. Meanwhile, with the increment number of DC fans, the PV panel temperature drops significantly. As a conclusion, the optimum number of DC fans is two with the combination of inlet airflow.

Age Modulates Physiological Responses during Fan Use under Extreme Heat and Humidity.

Science.gov (United States)

Gagnon, Daniel; Romero, Steven A; Cramer, Matthew N; Kouda, Ken; Poh, Paula Y S; Ngo, Hai; Jay, Ollie; Crandall, Craig G

2017-11-01

We examined the effect of electric fan use on cardiovascular and thermoregulatory responses of nine young (26 ± 3 yr) and nine aged (68 ± 4 yr) adults exposed to extreme heat and humidity. While resting at a temperature of 42°C, relative humidity increased from 30% to 70% in 2% increments every 5 min. On randomized days, the protocol was repeated without or with fan use. HR, core (Tcore) and mean skin (Tsk) temperatures were measured continuously. Whole-body sweat loss was measured from changes in nude body weight. Other measures of cardiovascular (cardiac output), thermoregulatory (local cutaneous and forearm vascular conductance, local sweat rate), and perceptual (thermal and thirst sensations) responses were also examined. When averaged over the entire protocol, fan use resulted in a small reduction of HR (-2 bpm, 95% confidence interval [CI], -8 to 3), and slightly greater Tcore (+0.05°C; 95% CI, -0.13 to 0.23) and Tsk (+0.03°C; 95% CI, -0.36 to 0.42) in young adults. In contrast, fan use resulted in greater HR (+5 bpm; 95% CI, 0-10), Tcore (+0.20°C; 95% CI, 0.00-0.41), and Tsk (+0.47°C; 95% CI, 0.18-0.76) in aged adults. A greater whole-body sweat loss during fan use was observed in young (+0.2 kg; 95% CI, -0.2 to 0.6) but not aged (0.0 kg; 95% CI, -0.2 to 0.2) adults. Greater local sweat rate and cutaneous vascular conductance were observed with fan use in aged adults. Other measures of cardiovascular, thermoregulatory, and perceptual responses were unaffected by fan use in both groups. During extreme heat and humidity, fan use elevates physiological strain in aged, but not young, adults.

Influence of rebinning on the reconstructed resolution of fan-beam SPECT

International Nuclear Information System (INIS)

Koole, M.; D'Asseler, Y.; Staelens, S.; Vandenberghe, S.; Eede, I. van den; Walle, R. van de; Lemahieu, I.

2002-01-01

Aim: Fan-beam projection data can be rebinned to a parallel-beam geometry. This rebinning operation allows these data to be reconstructed with algorithms for parallel-beam projection data. The advantage of such an operation is that a dedicated projection/backprojection step for fan-beam geometry doesn't need to be developed. In clinical practice bilinear interpolation is often used for this rebinning operation. The aim of this study is to investigate the influence of the rebinning operation on the resolution properties of the reconstructed SPECT-image. Materials and methods: We have simulated the resolution properties of a fan-beam collimator, used in clinical routine, by means of a dedicated projector operation which models the distance dependent sensitivity and resolution of the collimator. With this projector, we generated noise-free sinograms for a point source located at various distances from the center of rotation. The number of angles of these sinograms varied from 60 to 180, corresponding to a step angle of 6 to 2 degrees. These generated fan-beam projection data were reconstructed directly with a filtered backprojection algorithm for fan-beam projection data, which consists of weighting and filtering the projection data with a ramp filter and of a weighted backprojection. Next, the generated fan-beam projection data were rebinned by means of bilinear interpolation and reconstructed with standard filtered backprojection for parallel-beam data. A two-dimensional Gaussian was fitted to the two point sources, one reconstructed with FBP for fan-beam and one reconstructed with FBP for parallel-beam after rebinning, yielding an estimate for the reconstructed Full Width at Half Maximum (FWHM) in the radial and tangential direction, for different locations in the field of view. Results: Results show little difference in resolution degradation in the radial direction between direct reconstruction and reconstruction after rebinning. However, significant loss in

Aeromechanics Analysis of a Distortion-Tolerant Fan with Boundary Layer Ingestion

Science.gov (United States)

Bakhle, Milind A.; Reddy, T. S. R.; Coroneos, Rula M.; Min, James B.; Provenza, Andrew J.; Duffy, Kirsten P.; Stefko, George L.; Heinlein, Gregory S.

2018-01-01

A propulsion system with Boundary Layer Ingestion (BLI) has the potential to significantly reduce aircraft engine fuel burn. But a critical challenge is to design a fan that can operate continuously with a persistent BLI distortion without aeromechanical failure -- flutter or high cycle fatigue due to forced response. High-fidelity computational aeromechanics analysis can be very valuable to support the design of a fan that has satisfactory aeromechanic characteristics and good aerodynamic performance and operability. Detailed aeromechanics analyses together with careful monitoring of the test article is necessary to avoid unexpected problems or failures during testing. In the present work, an aeromechanics analysis based on a three-dimensional, time-accurate, Reynolds-averaged Navier-Stokes computational fluid dynamics code is used to study the performance and aeromechanical characteristics of the fan in both circumferentially-uniform and circumferentially-varying distorted flows. Pre-test aeromechanics analyses are used to prepare for the wind tunnel test and comparisons are made with measured blade vibration data after the test. The analysis shows that the fan has low levels of aerodynamic damping at various operating conditions examined. In the test, the fan remained free of flutter except at one near-stall operating condition. Analysis could not be performed at this low mass flow rate operating condition since it fell beyond the limit of numerical stability of the analysis code. The measured resonant forced response at a specific low-response crossing indicated that the analysis under-predicted this response and work is in progress to understand possible sources of differences and to analyze other larger resonant responses. Follow-on work is also planned with a coupled inlet-fan aeromechanics analysis that will more accurately represent the interactions between the fan and BLI distortion.

Queering the media mix: The female gaze in Japanese fan comics

Directory of Open Access Journals (Sweden)

Kathryn Hemmann

2015-09-01

Full Text Available The Japanese expression "media mix" refers to multimedia marketing strategies for entertainment franchises. Although such franchises are commonly understood as being controlled by large corporations, the fans of these media properties make significant contributions to the mix, often expanding on the central themes of the source texts and queering them by rendering their subtexts explicit. In dōjinshi, or self-published fan comics, female readers create their own interpretations of stories, characters, and relationships in narratives targeted at a male demographic. In BL (boys' love fan comics, which are notable for their focus on a romantic and often physical relationship between two male characters, the female gaze has created its own overtly homoerotic readings and interpretations that creatively subvert the phallocentrism implicit in many mainstream narratives. The interactions between texts and their readers found in dōjinshi illustrate how cycles of narrative production and consumption have changed in the face of active fan cultures. Because of the closely interrelated nature of the components of increasingly international media mixes, communities of fans have the potential to make positive and progressive contributions to the media mix ecosystem.

Human FAN1 promotes strand incision in 5'-flapped DNA complexed with RPA.

Science.gov (United States)

Takahashi, Daisuke; Sato, Koichi; Hirayama, Emiko; Takata, Minoru; Kurumizaka, Hitoshi

2015-09-01

Fanconi anaemia (FA) is a human infantile recessive disorder. Seventeen FA causal proteins cooperatively function in the DNA interstrand crosslink (ICL) repair pathway. Dual DNA strand incisions around the crosslink are critical steps in ICL repair. FA-associated nuclease 1 (FAN1) is a DNA structure-specific endonuclease that is considered to be involved in DNA incision at the stalled replication fork. Replication protein A (RPA) rapidly assembles on the single-stranded DNA region of the stalled fork. However, the effect of RPA on the FAN1-mediated DNA incision has not been determined. In this study, we purified human FAN1, as a bacterially expressed recombinant protein. FAN1 exhibited robust endonuclease activity with 5'-flapped DNA, which is formed at the stalled replication fork. We found that FAN1 efficiently promoted DNA incision at the proper site of RPA-coated 5'-flapped DNA. Therefore, FAN1 possesses the ability to promote the ICL repair of 5'-flapped DNA covered by RPA. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Local heat transfer performance and exit flow characteristics of a miniature axial fan

International Nuclear Information System (INIS)

Stafford, Jason; Walsh, Ed; Egan, Vanessa

2010-01-01

Dimensional restrictions in electronic equipment have resulted in miniaturization of many existing cooling technologies. In addition to this, cooling solutions are required to dissipate increased thermal loads to maintain component reliability. Axial fans are widely used in electronics cooling to meet such thermal demands. However, if the extent of non-uniform heat transfer rates, produced by highly three-dimensional air patterns is unknown in the design stages, premature component failure may result. The current study highlights these non-uniformities in heat transfer coefficient, using infrared thermography of a miniature axial fan impinging air on a flat plate. Fan rotational speed and distance from the flat plate are varied to encompass heat transfer phenomena resultant from complex exit air flow distribution. Local peaks in heat transfer coefficient have been shown to be directly related to the air flow and fan motor support interaction. Optimum locations for discrete heat source positioning have been identified which are a function of fan to plate spacing and independent of fan rotational speed when the Reynolds number effect is not apparent.

Numerical Study of Transition of an Annular Lift Fan Aircraft

Directory of Open Access Journals (Sweden)

Yun Jiang

2016-09-01

Full Text Available The present study aimed at studying the transition of annular lift fan aircraft through computational fluid dynamics (CFD simulations. The oscillations of lift and drag, the optimization for the figure of merit, and the characteristics of drag, yawing, rolling and pitching moments in transition are studied. The results show that a two-stage upper and lower fan lift system can generate oscillations of lift and drag in transition, while a single-stage inner and outer fan lift system can eliminate the oscillations. The characteristics of momentum drag of the single-stage fans in transition are similar to that of the two-stage fans, but with the peak of drag lowered from 0.63 to 0.4 of the aircraft weight. The strategy to start transition from a negative angle of attack −21° further reduces the peak of drag to 0.29 of the weight. The strategy also reduces the peak of pitching torque, which needs upward extra thrusts of 0.39 of the weight to eliminate. The peak of rolling moment in transition needs differential upward thrusts of 0.04 of the weight to eliminate. The requirements for extra thrusts in transition lead to a total thrust–weight ratio of 0.7, which makes the aircraft more efficient for high speed cruise flight (higher than 0.7 Ma.

Fan array wind tunnel: a multifunctional, complex environmental flow manipulator

Science.gov (United States)

Dougherty, Christopher; Veismann, Marcel; Gharib, Morteza

2017-11-01

The recent emergence of small unmanned aerial vehicles (UAVs) has reshaped the aerospace testing environment. Traditional closed-loop wind tunnels are not particularly suited nor easily retrofit to take advantage of these coordinated, controls-based rotorcraft. As such, a highly configurable, novel wind tunnel aimed at addressing the unmet technical challenges associated with single or formation flight performance of autonomous drone systems is presented. The open-loop fan array wind tunnel features 1296 individually controllable DC fans arranged in a 2.88m x 2.88m array. The fan array can operate with and without a tunnel enclosure and is able to rotate between horizontal and vertical testing configurations. In addition to standard variable speed uniform flow, the fan array can generate both unsteady and shear flows. Through the aid of smaller side fan array units, vortex flows are also possible. Conceptual design, fabrication, and validation of the tunnel performance will be presented, including theoretical and computational predictions of flow speed and turbulence intensity. Validation of these parameters is accomplished through standard pitot-static and hot-wire techniques. Particle image velocimetry (PIV) of various complex flows will also be shown. This material is based upon work supported by the Center for Autonomous Systems and Technologies (CAST) at the Graduate Aerospace Laboratories of the California Institute of Technology (GALCIT).

Design Optimization of a Centrifugal Fan with Splitter Blades

Science.gov (United States)

Heo, Man-Woong; Kim, Jin-Hyuk; Kim, Kwang-Yong

2015-05-01

Multi-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.

Facilitating Attuned Interactions: Using the FAN Approach to Family Engagement

Science.gov (United States)

Gilkerson, Linda

2015-01-01

Erikson Institute's Fussy Baby Network® (FBN) is a national model prevention program known for its approach to family engagement called the FAN (Gilkerson & Gray, 2014; Gilkerson et al., 2012). The FAN is both a conceptual framework and a practical tool to facilitate attunement in helping relationships and promote reflective practice. This…

Using Fan Fiction to Teach Critical Reading and Writing Skills

Science.gov (United States)

Kell, Tracey

2009-01-01

In this article, the author talks about fan fiction, which is defined by Jenkins (2008) as "original stories and novels which are set in the fictional universe of favorite television series, films, comics, games or other media properties." Fan fiction generally involves writing stories with a combination of established characters and established…

Volcanogenic Fluvial-Lacustrine Environments in Iceland and Their Utility for Identifying Past Habitability on Mars

Directory of Open Access Journals (Sweden)

Claire Cousins

2015-02-01

Full Text Available The search for once-habitable locations on Mars is increasingly focused on environments dominated by fluvial and lacustrine processes, such as those investigated by the Mars Science Laboratory Curiosity rover. The availability of liquid water coupled with the potential longevity of such systems renders these localities prime targets for the future exploration of Martian biosignatures. Fluvial-lacustrine environments associated with basaltic volcanism are highly relevant to Mars, but their terrestrial counterparts have been largely overlooked as a field analogue. Such environments are common in Iceland, where basaltic volcanism interacts with glacial ice and surface snow to produce large volumes of meltwater within an otherwise cold and dry environment. This meltwater can be stored to create subglacial, englacial, and proglacial lakes, or be released as catastrophic floods and proglacial fluvial systems. Sedimentary deposits produced by the resulting fluvial-lacustrine activity are extensive, with lithologies dominated by basaltic minerals, low-temperature alteration assemblages (e.g., smectite clays, calcite, and amorphous, poorly crystalline phases (basaltic glass, palagonite, nanophase iron oxides. This paper reviews examples of these environments, including their sedimentary deposits and microbiology, within the context of utilising these localities for future Mars analogue studies and instrument testing.

Volcanogenic fluvial-lacustrine environments in iceland and their utility for identifying past habitability on Mars.

Science.gov (United States)

Cousins, Claire

2015-02-16

The search for once-habitable locations on Mars is increasingly focused on environments dominated by fluvial and lacustrine processes, such as those investigated by the Mars Science Laboratory Curiosity rover. The availability of liquid water coupled with the potential longevity of such systems renders these localities prime targets for the future exploration of Martian biosignatures. Fluvial-lacustrine environments associated with basaltic volcanism are highly relevant to Mars, but their terrestrial counterparts have been largely overlooked as a field analogue. Such environments are common in Iceland, where basaltic volcanism interacts with glacial ice and surface snow to produce large volumes of meltwater within an otherwise cold and dry environment. This meltwater can be stored to create subglacial, englacial, and proglacial lakes, or be released as catastrophic floods and proglacial fluvial systems. Sedimentary deposits produced by the resulting fluvial-lacustrine activity are extensive, with lithologies dominated by basaltic minerals, low-temperature alteration assemblages (e.g., smectite clays, calcite), and amorphous, poorly crystalline phases (basaltic glass, palagonite, nanophase iron oxides). This paper reviews examples of these environments, including their sedimentary deposits and microbiology, within the context of utilising these localities for future Mars analogue studies and instrument testing.

Perceptions on the effect of small electric fans on comfort inside bed nets in southern Ghana: a qualitative study.

Science.gov (United States)

Jaeger, Mulako S; Briët, Olivier J T; Keating, Joseph; Ahorlu, Collins K; Yukich, Joshua O; Oppong, Samuel; Nardini, Peter; Pfeiffer, Constanze

2016-12-01

Long-lasting insecticidal nets (LLINs) are known to be highly effective in reducing malaria transmission, morbidity and mortality. However, among those owning an LLIN, use rates are often suboptimal. A reported barrier to bed net use is discomfort due to heat. This qualitative study was part of a larger evaluation conducted in communities without electricity in rural Ghana to assess whether 0.8 W solar powered net fans can increase net use. Twenty-three key informant interviews with household heads in the study communities in Shai-Osudoku District, southern Ghana, were conducted from July to August 2015. The purpose of the interviews was to obtain insight into perceptions of participants about the net fan system in relation to LLIN use. While all study participants reported using LLINs, with mosquito nuisance prevention as the prime motivation, heat was also mentioned as a key barrier to net use. Respondents appreciated the net fans because they improved comfort inside bed nets. The LED light on the fan stand became the main source of light at night and positively influenced the perception of the intervention as a whole. The general acceptance of the net fan system by the study participants highlights the potential of the intervention to improve comfort inside mosquito nets. This, therefore, has a potential to increase bed net use in areas with low access to electricity.

Study on detailed geological modelling for fluvial sandstone reservoir in Daqing oil field

Energy Technology Data Exchange (ETDEWEB)

Zhao Hanqing; Fu Zhiguo; Lu Xiaoguang [Institute of Petroleum Exploration and Development, Daqing (China)

1997-08-01

Guided by the sedimentation theory and knowledge of modern and ancient fluvial deposition and utilizing the abundant information of sedimentary series, microfacies type and petrophysical parameters from well logging curves of close spaced thousands of wells located in a large area. A new method for establishing detailed sedimentation and permeability distribution models for fluvial reservoirs have been developed successfully. This study aimed at the geometry and internal architecture of sandbodies, in accordance to their hierarchical levels of heterogeneity and building up sedimentation and permeability distribution models of fluvial reservoirs, describing the reservoir heterogeneity on the light of the river sedimentary rules. The results and methods obtained in outcrop and modem sedimentation studies have successfully supported the study. Taking advantage of this method, the major producing layers (PI{sub 1-2}), which have been considered as heterogeneous and thick fluvial reservoirs extending widely in lateral are researched in detail. These layers are subdivided into single sedimentary units vertically and the microfacies are identified horizontally. Furthermore, a complex system is recognized according to their hierarchical levels from large to small, meander belt, single channel sandbody, meander scroll, point bar, and lateral accretion bodies of point bar. The achieved results improved the description of areal distribution of point bar sandbodies, provide an accurate and detailed framework model for establishing high resolution predicting model. By using geostatistic technique, it also plays an important role in searching for enriched zone of residual oil distribution.

Fluvial Connectivity and Sediment Dispersal within Continental Extensional Basins; Assessment of Controlling Factors using Numerical Modelling

Science.gov (United States)

Geurts, A., Jr.; Cowie, P. A.; Gawthorpe, R.; Huismans, R. S.; Pedersen, V. K.

2017-12-01

Progressive integration of drainage networks has been documented in many regional-scale studies of extensional continental systems. While endorheic drainage and lake sedimentation are common features observed in basin stratigraphy, they often disappear from the record due to the development of a through-going river network. Because changes in the fluvial connectivity of extensional basins have profound impact on erosion and sediment dispersal, and thus the feedback between surface processes and tectonics, it is of great importance to understand what controls them. Headward erosion (also called headward capture or river piracy) is often suggested to be the main mechanism causing basins to become interconnected over time with one another and with the regional/coastal drainage network. We show that overspill mechanisms (basin over-filling or lake over-spilling) play a key role in the actively extending central Italian Apennines, even though this area is theoretically favorable for headward erosion (short distances to the coast in combination with rapid surface uplift). In other tectonic settings (e.g. contractional basins and high plateaux) the role of headward erosion in transverse drainage development and integrating endorheic basins has also been increasingly questioned. These two mechanisms predict very different spatio-temporal patterns of sediment dispersal and thus timing of sediment loading (or erosional unloading) along active normal faults, which in turn may influence the locus of subsequent extensional deformation. By means of surface process modelling we develop a process-based understanding of the controls on fluvial connectivity between extensional basins in the central Italian Apennines. We focus on which conditions (tectonic and erosional) favour headward erosion versus overspill and compare our model results with published field evidence for drainage integration and the timing of basin sedimentation/incision.

A multi-scale approach of fluvial biogeomorphic dynamics using photogrammetry.

Science.gov (United States)

Hortobágyi, Borbála; Corenblit, Dov; Vautier, Franck; Steiger, Johannes; Roussel, Erwan; Burkart, Andreas; Peiry, Jean-Luc

2017-11-01

Over the last twenty years, significant technical advances turned photogrammetry into a relevant tool for the integrated analysis of biogeomorphic cross-scale interactions within vegetated fluvial corridors, which will largely contribute to the development and improvement of self-sustainable river restoration efforts. Here, we propose a cost-effective, easily reproducible approach based on stereophotogrammetry and Structure from Motion (SfM) technique to study feedbacks between fluvial geomorphology and riparian vegetation at different nested spatiotemporal scales. We combined different photogrammetric methods and thus were able to investigate biogeomorphic feedbacks at all three spatial scales (i.e., corridor, alluvial bar and micro-site) and at three different temporal scales, i.e., present, recent past and long term evolution on a diversified riparian landscape mosaic. We evaluate the performance and the limits of photogrammetric methods by targeting a set of fundamental parameters necessary to study biogeomorphic feedbacks at each of the three nested spatial scales and, when possible, propose appropriate solutions. The RMSE varies between 0.01 and 2 m depending on spatial scale and photogrammetric methods. Despite some remaining difficulties to properly apply them with current technologies under all circumstances in fluvial biogeomorphic studies, e.g. the detection of vegetation density or landform topography under a dense vegetation canopy, we suggest that photogrammetry is a promising instrument for the quantification of biogeomorphic feedbacks at nested spatial scales within river systems and for developing appropriate river management tools and strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geomorphic investigation of the Late-Quaternary landforms in the ...

Indian Academy of Sciences (India)

Shubhra Sharma

2018-02-14

Feb 14, 2018 ... preserve a rich repository of the glacial and fluvial landforms, alluvial fans, and lacustrine deposits. Based ... The multi-millennial scale climatic fluctuations are ...... Villages environment, resources, society and religion life.

High fidelity phase locked PIV measurements analysing the flow fields surrounding an oscillating piezoelectric fan

International Nuclear Information System (INIS)

Jeffers, Nicholas; Nolan, Kevin; Stafford, Jason; Donnelly, Brian

2014-01-01

Piezoelectric fans have been studied extensively and are seen as a promising technology for thermal management due to their ability to provide quiet, reliable cooling with low power consumption. The fluid mechanics of an unconfined piezoelectric fan are complex which is why the majority of the literature to date confines the fan in an attempt to simplify the flow field. This paper investigates the fluid mechanics of an unconfined fan operating in its first vibration frequency mode. The piezoelectric fan used in this study measures 12.7 mm × 70 mm and resonates at 92.5 Hz in air. A custom built experimental facility was developed to capture the fan's flow field using phase locked Particle Image Velocimetry (PIV). The phase locked PIV results are presented in terms of vorticity and show the formation of a horse shoe vortex. A three dimensional A2 criterion constructed from interpolated PIV measurements was used to identify the vortex core in the vicinity of the fan. This analysis was used to clearly identify the formation of a horse shoe vortex that turns into a hairpin vortex before it breaks up due to a combination of vortex shedding and flow along the fan blade. The results presented in this paper contribute to both the fluid dynamics and heat transfer literature concerning first mode fan oscillation.

Towards engagement: A comparison of fan groups in the context of a major South African football club

Directory of Open Access Journals (Sweden)

Frederick W. Stander

2016-07-01

Full Text Available Orientation: The commercial growth of sport clubs is often a direct consequence of the level of engagement of its fans. However, limited research has been done to understand how the engagement experience of these fans could be enhanced. Research purpose: The objective of this research was to evaluate whether differences exist amongst groups of sport fans in terms of their levels of engagement. This is conducted on the basis of customer engagement – relationship marketing – and market segmentation theories,and in an effort to inform practical strategies that could be used to leverage engagement. By establishing that differences do exist between segments of sport fans, practical strategies could be developed based on such differences. Research approach, design and method: A cross-sectional, quantitative design was utilised in this study. A convenience sample of 430 adult fans of one of South Africa’s largest and best supported professional football clubs participated in the study. Two fan groupings were compared, namely fans who belonged to a formal supporters’ branch of the club versus fans who did not, and fans who frequented the social media platforms of such club versus fans who did not. Multi group confirmatory factor analysis and latent variable modelling were implemented to compare groups of fans in terms of sport fan engagement. Measurement invariance was reviewed to compare the equivalence of measurement between the groups. Main findings: Statistical analysis revealed greater levels of fan engagement amongst fans that form part of formal supporters’ branches as well as amongst fans who regularly visit the sport club’s social media platforms. Practical/managerial implications: By making use of supporters’ branches and social media,practical engagement strategies are available to professional sport clubs that seek to enhance the engagement experience of their fans. These strategies could assist clubs in developing customised